This is a lot less complicated than what people are making it out to be. I wouldn't expect any degreaser to work well for your application. Grease has a tendency to be slippery, and I'd expect brakecrud to made out of non-slippery things. You say that you have water spots on your wheels. Mind you, this will likely be noticed by no other human on the planet but you. Ever. It's part of the HD culture though, so don't sweat it. My suggestion is to use a minimal amount of cleaner that is designed to remove the hardwatercrud that causes the water spots. A dab of CLR or LimeAway ought to do the trick. I'm not a chemical engineer, but I'd immediately rinse and dry any spot of my precious that the CLR touched. Brakedust is a separate issue. It wipes away easily until it pits. Some people have mentioned wheel wax. Because wheel wax is... wax, it has a tendency to soften when exposed to heat, like the type of heat that something bolted to a brake rotor might experience. I think it's reasonable to expect molten wax on a wheel to catch crap like brake dust, so I would just forgo wax and let the hard clearcoat on the wheels do what it's supposed to do - provide a clear and hard protective barrier.