what should I use to clean my plate after printing with PETG?

I've never really thought much about something specific for petg.

I use a magnetic pei bed, both textured and non textured with a glue stick layer.

I don't often need to clean but I'll use soap and water in the sink for the majority and then a isopropyl squirt and rub with a rag. Then I reapply glue stick.

This lasts a lot of prints for me for pla, petg and abs.

Really, I'd think you would need to avoid chemicals that would react with your bed and make sure there is no residue left by your cleaner. For my pei bed I bet I could even use acetone. Beyond that... Happy washing.

There are lots of internet gudes on this. Here is one random one I just found. https://www.wevolver.com/article/how-to-clean-3d-printer-beds-glass-pei-adhesive