Since my car is black, I am a freak about road dust. Everytime I come home from any kind of driving, I just use a Cobra microfiber and Pinnacle QD to wipe the dust off. Of course that makes half of the microfiber dirty because the dust actually sticks to the microfiber. I use a quarter of the microfiber for half of my car, and a quarter for the other half. This all takes about 15-20 minutes. Easy.
I use the waterless wash if there is heavy dust/other junk. Its more of a WASH rather than a quick clean up. That sort of explained it, just my methods of using em