Net positive

It's easy.

Deny
Take control
Show empathy
Start their departure.
Make them glad they're leaving

Cut them off, "Oh, sorry. I'm not interested in that. I need to quickly get back to what I was doing. But you have a good day and try stay cool/warm/dry/etc. out there." Start stepping back, "And be careful of the dog four doors down, it's a fucking cunt."

As you close the door, say "You too, bud." regardless of what they say, even if they say nothing.

They will never return or pursue, and you won't feel rude.

It's ok to be rude. They were rude for showing up at your door in the first place.
- Eh, I save rude for the second "Leave." It's a human being on the other side of the door. Half the time it's some kid who just needed a job summer before college. I say hey, I don't want solar panels right now, have a nice day.
  
  Now, when you tell me to wait, as you stand on my porch, then I'm going to tell you to get off my porch. I still say please though, because my kids might be listening, and I strive to use good manners in all my interactions, in the hopes they will too. You can be firm and polite.
- I sympathise that they are currently in a period in their life where they are doing door-to-door sales for a wage.
- Yep not to mention they are preying on you feeling rude and will take FULL advantage if you show any opportunity.
I did this and now my son is crying. Are you sure that's good advice?

Edit: I might have misunderstood something
- salemen use children to pull on your heartstrings. No mercy!
here's what we do,
A: don't open the door if you see it in advance, however our house is built where other than our electric doorbell we can't see who's at the door, peephole is old and foggy.
B: "oh no thanks we're not interested" often filled with a "no dangit [dogs name] stop barking" / "get back" then close the door because the dog is trying to get out

No external factor is necessary to "get you out of" talking to a door-to-door salesman. It really is as simple as saying "get the fuck off my property" and slamming the door in their face.

You can be nice and firm. "I'm not interested. Have a day" and then shut the door. They're just doing their job no need to be an asshat ;) seems a lot of people are so afraid of conflict they'll allow people to monopolize their time simply to save the embarassment of saying leave me tf alone.
I accidentally answered the door for salespeople ONCE.

I bought what they were selling.

They asked “do you want to save money on your internet?”

I said “no thank you, I’d rather pay more for no caps and faster internet.”

They told me “we just rolled out gigabit on this block”

fuckin shit… you got me. It was also STILL cheaper.
- I wish that would happen to me. There's two big companies that service most of my area, one is cable, the other is DSL. The DSL provider, whenever I've checked, only offers 10Mbps download. Big nope from me. Cable has gigabit, but capped at 30mbps upload.
  
  There's a third regional provider that operates in my area that does fiber exclusively (plus a bunch of resellers and wireless providers). The fiber company doesn't serve my address. Just me though.... Well, my side of the street. If I put in my neighbors address into their service form, it says they're capable of getting gigabit up and down for a very reasonable price. I put in mine, and "sorry, we don't serve your address" or whatever. I think that's because the utility poles are on the other side of the street, and they're on the poles, but don't have a permit to cross the street (generally by aerial lines)... Which is what the cable provider did when I finally purchased their service; they ran a line over the road to my house.
  
  Upload is important to me, and 10:1 speeds are fine, but 30:1 or more, no thanks. The plan I went for was 300/30, which is the fastest upload they offer with the slowest download (the 200mbps plan was 20mbps upload or something, and the gigabit was 30mbps upload).... I want fiber.
  
  If that regional fiber company knocked on my door saying that they service my area now, I'd ask where I sign.
  
  And before anyone asks: I contacted them about it and they said something about the permits and blah, and blah. I've tried to contact them several times about how I can help get them the permits to operate in my area more broadly (including my address), but they have not responded. I'm happy to petition my town hall or regional governmental office to push things along or even canvassing for signatures on a petition to give them the required permits to serve the area.... Even paying for a portion of the permit cost if necessary.... Not a word from them.
  
  Feels bad.
We finally got a “no soliciting” sign and it’s insane how much it actually works. I had just assumed people would ignore it and it’d be as useless as the do not call list. But I was wrong and people turn their ass around before ringing the doorbell
- Me too. My SO is too fucking nice. I love her for being so nice, but I caught her giving way too much personal info to some random solicitor. When I asked her why she would do that she “felt bad” for him. Nope, not having that, and the sign has worked wonders by preventing all contact in the first place. Can’t feel guilty if you don’t engage.
or just say you're satanic
- That would get rid of Jehovah's Witnesses, but I see little reason to think it was would necessarily be effective on salespeople.
  
  If, for some reason, you're unwilling to treat these worthless in-person spammers with the contempt they deserve, my suggestion is to remember that "no" is a complete sentence.

I just say no and shut the door. I don't say it rudely but I also don't wait for a response. It's really not that hard?

Generally they delay answering who they are for this exact reason. If they engage you before you say no, they are more likely to pressure your u into listening

@aeronmelon who opens their door anymore when someone knocks?

I do, for when a neighbor kid kicked a ball in my yard and they are asking for it back.
Unless I'm expecting you, there's no point. You don't need to know my schedule or what the inside of my house looks like.
- @thesystemisdown right anyone I'm expecting will have called first. Everybody else can fuck right off. XD
I set up a sensor so I know not to go downstairs if someone is at the door. I'm not putting on pants.
- I can hear that neighbors kid screaming now, promising never to bother you again

Cable? What year is this?

That's why they have door to door salesman now, they're getting desperate lol
Cable has negative value to me. I don't get why anyone would want to pay to have a line serve them so many ads. And the cheap cable package is garbage on the content side, too.
- I could never go back to cable and don’t understand what too me so long to cut the cable (yay COViD? For pushing me over that edge). But there are still a lot of people with a lot of inertia. I assume cable companies are just trying to hold onto their remaining customers long enough to build more profit into their internet offerings.
  
  They may also be preying on their elderly customers finding it difficult to make the paradigm jump to streaming
  
  That being said, streaming has a gap in local broadcast coverage that’s more easily filled with cable
  
  not everyone can, or is aware they can use an antenna
  
  local streaming like Hulu is expensive
  
  sports streaming is expensive plus per sport
  
  I rarely miss local broadcasts, with only a few exceptions such as presidential debates and the Super Bowl

Have you tried just looking young? My sister answered the door (of the house she owned) and it was some sales person who asked her if her parents were home. She said no and closed the door.

Doesn’t work. My teen had the opposite. Despite insisting he was just a kid, they still tried to sell him solar power panels. He’s a good kid though: he knew not to bother me

my favorite story of door to door salesman is when some unmarked white van came around the neighborhood selling meat. My dad opened the door said "sorry... we, uh, we're all vegans" in the most awkward manner, the dude 100% knew it was a lie but just said "yeah alright sorry for bothering ya" and left

Haven't seen the van meat man other than that 1 time, no idea why he was selling meat out of a creepy white van but I hope it's not what I'm thinking. I wonder where he is now

I got the case once: someone was selling potatoes door to door from a weird van.

We got a few robberies in the village a bit later and the police told us that the people were actually checking all houses to see who was here or not and which houses were worth it.
That’s actually legitimately scary.

As a child, I was suspicious of the Swanson Ice Cream trucks that randomly appeared in my neighborhood.