get yourself an ez detail wheel brush or similar, bilberry wheel cleaner or megs apc.
pre-spray your wheels with a 50/50 mix and allow to dwell for 5 mins or so, spray a bit of neat solutuion on your brush and clean away, apply more solution to the wheel if needed brush again then rinse off well,
to help keep them cleaner for longer and to make it easier too clean is seal and wax them on a regular basis, this will make life alot easier.
