look up zodi showers.....I bought the double propane bottle unit for a cargo trailer hunting rig I am building....have not used it yet....but did research and came up with this......bob
They work real well for car camping. I used to meet up with a bunch of friends from up and down the west coast. One of the gals has real long hair, past her butt. She had a 2 burner Zodi. After about 3 years I caved in ("real men bathe in the crick") and tried it ... it's GOOD. Set it up inside one of the biggest "privacy shelters" (aka shiitter shacks) you can find with a piece of cheap indoor outdoor carpet for a floor .. especially good on gravel. I bought the one burner unit .. probably a mistake. I run the water through it twice, once as a pre-heat, the second time to shower. I'm done with the creek outside of July / August.
If you want to do it on the cheap, get the Zodi pump / showerhead / hose, heat water over the campfire, and mix with creek water to reach whatever temperature floats your boat ... use a cheap 5 gallon bucket to hold the hot water while you shower.
The "shiitter shacks" are good amusement .. watching people try to re-fold them for transport. They'd make a preacher cuss.
Tom