Make sure the nail polish remover actually has acetone in it and it is fairly fresh. Acetone can evaporate. I keep a small can of 100% acetone around.
Here is a good one that taught my buddy a quick lesson: Yellow jacket landed on a tire on his truck. He hates bees/wasps. He goes over to smack it with....a ballpeen hammer. He gets real close to make sure he doesn't miss... 2 butterfly stitches and a headache later...
I felt bad about not stopping him (later), but I really couldn't believe what I was seeing. Like watching a movie or something.