I recently noticed ick on one of my new neon tetras

I started dosing my tank with Tetra Ick guard, so I am not too worried about the fish. I am worried about my snail though. I know it won't get Ick, but I read that they can carry it, and I removed the snail from the tank because the medication can kill them! I am wondering how to make sure that he isn't carrying any Ick before adding him back to the tank once I am finished dosing Ick Guard. I don't want to have to go through the same issue over again once it is all cleared up because my snail was still carrying it.
By the way I am keeping him in a small plastic cup at the moment, because both my main and quarantine tank are being dosed with the medicine. Therefore I can't really raise the temp. Any other ideas would be greatly appreciated.