If you have birds, teflon fumes will kill them. Probably not too good for people either. I don't think it will get that hot if designed correctly.
No of course coffee roasters don't have teflon!! Why? There is no need for it, beans are not going to stick to the roasters. Not to mention the rocks and stuff that find their ways into roasters would probably do all kinds of terrible stuff to the teflon as well.
Lye might eat your base metal as well. It will eat the hell out of aluminum, so if it's a T coated aluminum pan, lye is a bad move, well, so is acid to be honest. If you want something a bit gentler,but would take a bit longer, try the stuff you clean your coffee pots with, let it soak on them a bit after scratching em up with a brillo pad.
or you could just polyurethane your stuff and not have to worry about the teflon coming off
Aaron