Lighter fluid, aka Naptha, is a pretty good solvent on most adhesives, but has some persistent flammability issues that I don't care for around electronics too much. I prefer to use aresols that are specifically made for electronics cleaning, like electro-wash, which are mild freon based solvents that leave no residue, are safe to use on electronic equipment, and won't hurt plastic in the least.
Electro-Wash It may not be as aggressive at removing/desolving the adhesive, but better to be conservative about such things in my opinion.