ALL knobs you clean with a hot dry mop rag. NOT WET. Like a dry mop. It needs hot moisture to clean the grooves but not discolor anything. If it smell like a solvent it is.. Pretty simple.. Keep that crap away from from anything plastic or dipped or some weird protective goop. New Mac Remotes really suck.. I got no idea what they were thinking.. They get gooey, no way to clean it either..
Knobs aren't cheap, unless you find someone that is selling out. There are a ton of them out there.. When and where?