Paint on tubs please help
if its latex paint, it will come off with a paint remover like goo be gone or goof off, if its oil paint, you can use brake fluid.  either approach will mean letting the liquid sit on the paint for a few hours or overnight.

however, as both will not damage enameled steel tubs, either can damage acrylic, fiberglass or epoxied tubs, but it depends on the model and what/how its made.  i would probably do a test on a single tub in a single unit to make sure it won't destroy the underlying finish.  

when all done, clean the area with a good degreaser and then some plain white vinegar (to neutralize the alkalinity of the degreaser)

hope that helps