In most cases you have to use a stronger dilution than recommended in an automatic with a wheel scrub because there is little or no dwell time to allow the chemical to do the job of lifting or loosening the soils. An alkaline product will do a better job of cleaning the wheels but not on the rims. Soil found on rims is basically carbon based brake dust covered by road film - a difficult combination to clean. Sometimes a really strong alkaline will work but in most cases a strong low pH does a better job. It also helps if the chemical solution is applied with hot water and there is a high pressure blast before and after the wheel scrub if that is possible. Outside of using a product containing Hydroflouric acid (which is not recommended) there is no magic bullet when it come to rims. A lot depends on your automatic's ability to apply and rinse the product properly.