You can now buy a combined version called Tar-X but it's quite expensive IMHO, though seems to get good reviews.
Personally I think the best approach (apart from getting someone else to do it
) is to get them really clean and then give them a coat of wax/sealant, even if it isn't specifically for wheels anything is better than nothing. Then ordinary car shampoo seems to work well...certainly on my work car that does anything up to 1,000 miles a week and gets washed maybe once a fortnight. If I leave it a bit too long then a diluted solution of Bilberry wheel cleaner (non acid
) left to soak while I wash the bodywork, seems to do the trick.
I used wonderwheels to clean the backs of my Z3 alloys which hadn't been done for 11 years I reckon. I did rinse them thoroughly afterwards, then de tarred and used Wolfs brake duster to remove iron deposits, polished then two coats of wheel sealant. I did try Bilberry, etc first but it just wouldn't touch the baked on dirt, so wonderwheels does have it's uses, just not every time you wash the car.
Before (left half has wonderwheels applied):
image
After:
image
Looks pretty good back on the car:
image
I also use an EZ brush and don't find it scratches my wheels, though I tend to just push it through the spokes to do the wheel backs. The fronts I do with a sponge (rather than risk getting grit on my wash mitt).