I remember trying to discourage my cat from eating christmas tree, i read somewhere that cats hate pepper, so i piled up quite a lot of it and then i had to stop him from eating christmas tree AND pepper.
Sounds like one of my cats, he will chew on literally anything.
The one thing I've found that works with all of my cats and my dog is lemon oil - they can't stand the stuff. I make a spray out of 70% rubbing alcohol and lemon oil (like 95:5 by volume) and spritz it around the tree every few days, they won't even come close.
Of course feral catgirls are real there are a bunch living behind my garage. Do you want a couple? We're running a catch spay release thing. They're not socialized at all, like if you try to pet a feral catgirl you'll get scratched. But with patience you can build trust to the point where they'll sit and watch JujutsuKaizen with you while they drink their iced coffee.