rnbradford- I thought I was the only person doing that! I go back and forth trying to decide if it uses too much more car wash or not, but it IS convenient! Especially with a separate hose on each side of the car also.
Gary H.- The idea is that you only use that bucket for rinsing your mitt/brush/whatever, thus keeping your wash solution from getting contaminated with the dirt from the car. No real point in having soap the rinse water. It does get soapy from the rinsing of the mitt/etc. anyhow.
Nick T.- Yeah, frequent refreshing of the rinse water is cheap insurance.