I had the same problem when i had turbines. Buy some Eagle one wheel cleaner or similar (spray bottle), before you wash the car, spray the wheels, let them soak for a few minutes, wash them off (high pressure, if possible) and shazam, clean wheels. Buy the spray with hcl in it and your wheels will be beautiful. No scrubing involved......the hcl would eat your hands to the bone. I used this method for years.