In addition to P21S (very good stuff, but costly $$$), I like a product called Simple Green. I pay about $20/Gallon for it, which will last me, oh, about forever. It requires work, but minimizes the work, never damages the wheel, is non-toxic and biodegradeable to boot. Of course, the organic brake material itself is carcenogenic, so maybe this doesn;t much matter :-) Grant