definitely do not use anything like acetone, cellulose thinners, ethyl
Have you considered caustic soda? Can be bought as a powder to mix
with water for paint stripping from DIY shops, or as drain cleaner and
thicken with something neutral say flour to form a paste. Very messy
but removes all except cellulose car paint, have been stripping
furniture covered in Lord knows what for years with it. PROTECT EYES -
SKIN - DON'T let SOLUTION OVERHEAT WHEN MIXING. Nasty stuff.