[speeder]

OK, I used *etching type* mag wheel cleaner that they sell at every FLAPS in the land. It's the one that warns you not to use it on chrome/clear coat/paint/anodised or basically any type of finish other than raw alloy. It's basically acid in a spray bottle. You simply spray it on, scrub w/ stiff bristle brush and then rinse. (Quickly). It will etch your driveway and anything else it touches, so precautionary measure must be taken and lots of rinsing.