Just be sure any disinfecting wipes don't have bleach of any kind. What Joe said. I have used Lysol Scrubbing Bubbles , but that is only in a DIRE emergency and then not on decals. Mold loves oil and that is why shoes sometimes mold and saddles. It is generally harmless and just looks awful and smells. Mold forms from moisture and dirt too. A friend recommended half a cake of Safeguard soap, still in the box, put inside the case of FWs and it should work on 301s and others too. Don't let it touch the machine. That is why it should be in its box.