one bucket with proper car shampoo, one with clean water. put lambswool mitt in soapy water, wash part of car, put into bucket of clean water to rinse the crap off the mitt. wring out mitt, back into the soapy water wash part of car, rinse in the clean water, wring out, back in soapy water etc etc etc etc. after all this, pour out the rinsing water slowly and see the amount of sh!te that otherwise would be in your washing water and in turn, rubbed all over your car. its all this crap that causes swirl marks!