I live near two rivers and a large freshwater lake. I plan to use a bucket and soap to get cleaned off, and then do a final rinse in a kiddie wading pool half filled with distilled water made over an open wood campfire in a fire pit. There are a lot of germs and bacteria in untreated water, so a final rinse will keep you from getting a case of the creeping crud, or worse.
In my BOBs/GHBs/hunting pack I use sanitary wet wipes in the foil packages. You can get boxes of 24 wipes at Wally World for ~$3.00. These work for sanitary purposes, and also for washing your hands just to eat, or cleaning a wound (these are antiseptic). I also keep a bottle of alcohol-based hand sanitizer in each pack, along with toilet paper and paper shop towels. I also keep a toothbrush, toothpaste, dental floss, and floss sticks, and a small bottle of Listerine -- also serves as a wound cleaner/antiseptic. And I keep a tube of Neosporin in with bandaids.
I also carry similar setups when I travel for work. So many surfaces you have to touch when you travel, so I use the wipes to clean my hands (and tray table on airplanes) before I eat.