A paint remover called "Peel Away" might do it. Used to be sold be Sherwin
Williams. Put it on as a thick paste. Cover with a special paper. Let sit for
24/36 hours. Remove paper and paste together. will remove up to 20 coats of
paint at once. Not very toxic. Not strong smell. Cleans up with water. Gets
paint out of cracks and places that are hard to clean with conventional paint
removers.

John Bassett