1.   Finally, try a little heat from a hair dryer to soften the plastic, but not enough heat to affect the finish.

2.   It is effective in removing all finishes, but it attacks and softens plastics.

3.   Solvents work by softening the plastic.

4.   Still another treatment is to use oil to soften the plastic so it can be scraped off.

5.   Try more water, but not too much, to soften the plastic so it can be scraped off with a wood spatula or other soft scraper.