We always use our simple yet effective method to clean car alloy wheels,We always rinse the vehicle down first either with a effective prewash or Snow Foam,Once rinsed we recommend using a Iron Fall-Out Remover because these are a strong yet wheel friendly product.
Simply spray the wheels with the product and leave to dwell for a few minutes,Then get a soft brush even a toothbrush and just agitate the product (Some Fall-Out removers go purple this is normal.)
Once agitated simply blast with the jet washer (Always stand approximately 1 metre away.) Dry with a soft microfibre cloth,Apply some wheel wax and tyre dressing and you will have clean wheels amongst the best on the road.
Iron-Fallout-Remover removes the toughest stains and can make old tired wheels look much younger we highly recommend the Glimmermann Iron-Fallout-Remover this is beause it can be diuted so a 500ml bottle can make 5 litres at a low £9.99 price this is not to be missed (yes we do use it ourselves).