I too use Meguiars wheel brightener with great results. 4:1 with spray let it sit for a min or two rinse then wheel brush with soapy water and I'm left with a clean looking wheel.
Malco brake off, it makes the stuff comes off in sheets with no agitation. I use meguiars wb at 4/1 for all but the nasty ones. Find brake off on y tube and it will amaze you!
