Simple green automotive degreeser works the best along with a good stiff (not wire, plastic!) brush. There are many companies that make metal sealants (some are wheel specifice, but they do the same damn thing) may wanna consider this. I used a product called Zoop Seal, worked amazing. You apply it to a sparkling clean wheel. After the product "soaks in" the wheel is permanently (for quite a long time) protected from anything and everyhting. Brake dust, oils, brake fluid grimey stuff, you name it, all you gotta do is hose it off (thats if any thing sticks to it.) Try that!
You'd like it.
Oh yeah, and there is also an automotive degreeser (multi purpose auto, might I add) called Blue Max. We use it at the dealership I work at... it's probably even better than simple green.
Try and stay away from wheel specific cleaners (like Eagle One wheel cleaner, wire fire rim cleaner, and all those others) some of these rpoducts can and will eat at the finish if you have ametallic silver painted wheel. Strangly, that is the only kind of wheel that can be affected, a dull silver, black, chrome or what have you, is not chemically affected. I ruined a set of E1's becuase of Eagle One (and they paid for them, too). They didn't say anything about testing before use... but now they do.
