misseva,
I'd use denatured alcohol to get the oil off the belt and pulleys myself.
Also at PetSmart the other day I saw a different type of aquarium tubing I'm going to try. The normal stuff like Wal-Mart sells is a clear plastic that's kind of slick. At PetSmart they had silicone tubing that actually had a sort of texture to the surface. They had it in black and clear. Not any more expensive than the Wal-Mart stuff, but I think it might work better.
Joe