What PEC-12 does superbly is remove sticky residue left behind from tape etc. I just picked up an 8x10 enlarger from a lab that used damned
masking tape all over the place. Obviously, one can't just grab a can of something like acetone that would attack paint too. So I use citrus
solvent to do most of the softening of the old tape, then resort to more expensive PEC for the final cleanup. I also often use when needing to
remove tape residue from neg carrier glass of when taping film masks to other sheets of film. Alas, even I can't avoid tape all the time!