Wheel Woolies are by far the safest, most effective way to clean automobile wheels on the market. Most wheel brushes do an excellent job at cleaning the outside surfaces of the wheel but do not allow the user to get into the small holes and crevices where the brake dust collects.  Twisted wire spoke brushes will reach in but they can really scratch up a wheel if used carelessly and they splatter you with wheel cleaning chemicals and dirty water.

Wheel Woolies Wheel & Rim Detailing Brushes