Might want to try Poorboy's Spray & Rinse wheel cleaner
I have been using this for some time. I 1st got a sample, and gave it to dad without trying it. At the time, I was of the thought that if you want them clean, you have to get in there and scrub them.
Dad used it on mom's Mini van, which is almost a cast wheel, and about the worst for brake dust. When I went over there the next weekend, he told me to get more of that, it cleaned them without touching them. I looked ( expecting dad's clean and mine to be 2 different things ), and I was shocked, the wheel had not looked that good in years.
Just got a chance 2 weekends ago to get before and after pictures on the sister in law's new to her ( used-03 ) Mustang. The car is in rough shape, and I have not clue when the last time the wheels had been cleaned.
Before
Front
Rear
After
Front
Rear
All I did was spray down a cold wheel with water.
Walk around spraying PB SnR on them.
Once I got done put down the bottle and put the correct end in the PW lance, and rinsed them off.
did not touch them, total dwell time ~ 7 mins
The rear wheel needed to be scrubbed, but I was not getting in there with a brush to get the little spots left on it.
I did not even dry them, air dry only ( can still see water on the front wheel in the after shot )
if you use a wheel sealant, you need to dilute the SnR to i think 50-50, PB's forum ( or I am sure it is on AG somewhere ) has the ratio. I gave up on using wheel sealant with how easy SnR is to use.