We used to tent camp alot, and bought a solar shower from walmart. It was a black plastic (two liter i think) bag with a hose on it and a small shower head. It was pretty cheap and worked well. But as mentioned, you have to have a place to hang it.
In the military some of us would take along a small one gallon hand pump pressurized bug sprayer, like you use to spray bugs and weeds. The advantage of that over the solar shower is you don't have to have a place to hang it. It gets the crevices clean without being a contortionist, and works pretty well if you are sitting down. if you want a hot shower you can add some heated (from your camp stove) water to it. But it doesn't get hot in the sun as well as the solar shower.
keith