IMO -- a good approach to cleaning
anything is to work from
mild to wild. Paint thinner (mineral spirits), lighter fluid, tranny fluid, rubbing alcohol or even butter should work given a bit of patience. Goof-off and similar products have such an aggressive mix of solvents that you stand a much greater chance of damage. I would think the goal is to break the bond between the old adhesive and the paint..not to actually melt the stuff.
...just my thoughts on the matter...