I bought an assortment package to try them out (Joann had them.), but I haven't used any of them much yet.
The tips are dense foam. I'm guessing that would not be appropriate for Gamsol. At any rate, I don't want to take a chance with experimentation! For using Gamsol in the tight areas, wouldn't you be better off with some tortillons (from art supply store)? They are pretty sharp and can be sand-papered to a point you like.