Up until I started doing waterless washes I was totally in the same school of thought. I believed there was no way you could safely clean a car without a bucket wash. If you do a waterless wash correctly, however, there is no risk to the paint.
I use Ultima waterless wash. It has a wax component and since I never drive my car in the rain, I don't even bother doing any additional waxing/sealing/coating. In my case, it is sufficient on its own. A 16oz bottle is ~$20 and the dilution is 0.5oz to 22oz of water. So less than a dollar a bottle. I use plenty of clean towels and by the time I do the wheels and door jambs, I use a whole 22oz bottle per wash. Look on youtube for proper technique. Obviously I wouldn't use this method on a very heavily soiled car.
Believe me, I though it was complete heresy before I started doing it. I wash my car once every two weeks and it's been 2 or 3 years since I last corrected my paint. Here is a recent pic of the paint. You be the judge.
