I carry a container cut from a 1-gallon milk jug when I hike. The container is about 5 inches high and weighs about an ounce. I use it and a small bandana (along with a few ounces of water) to get a sponge bath in the evenings. It is truly amazing how much trail dirt can be removed with just a few ounces of plain water and a bit of effort. …
I also carry a 2-ounce bottle of Isopropyl alcohol and some cotton balls. When I finish with my “bath” in the evenings, I apply some alcohol to a couple of cotton balls and clean and deodorize the “obvious” areas of my body (underarms, groin area, area between my buttocks and my feet).
Even better, warm the water for your sponge bath.
Out-of-context photo is the open air “throne toilet”, a breezy design eventually abandoned by Parks Canada. I could not resist throwing it into this post.