It's used by NASA, people! Astronauts use this stuff - in SPACE! Space, where travel makes water a precious commodity.
I've ranted on this blog before about daily showers and how, unless you do manual labor or work in a coal mine, showering every day is a waste of water. Believe you me, I love showers, baths, hot tubs and jacuzzis as much as the next person, but using water everyday to wash body parts that are mostly covered up in clothing is senseless to me. That, of course, leaves open the question of cleaning certain body parts over others , but I'll leave that for a different discussion.