I just use one of my older microfiber wash mitts. It gets in there nice and deep like (lol) and it is good enough to make the wheels look nice.
Oh, and +1 on the SONAX cleaner. Haven't been able to find anything that cleans as good as that stuff. As with all wheels, the dirtier they are the more scrubbing you'll need, but the SONAX makes it wipe off with one quick swipe.
If you're looking for a spray and rinse perfect cleaner, I don't think you'll ever find one though, and with these wheels you'll never get that accomplished.
'11 BMW E92 ///M3 - ZCP and DCT
'13 Toyota Tundra - 4x4 Platinum CrewMax, 5.7l iForce V8