I understand caveman didn't use soap, but is it possible that he did more than just rinse? Using mud for cleaning purposes is one thing that comes to mind. I see animals do it, while others lick themselves. I'd be interested to know more about the way ancient human stayed clean.
The next part of the question is for those with experience with using no soap and is NSFW, you've been warned:
How do you keep it clean and odorless around the anal region? I find myself using soap only there because it just doesn't feel right to simply rinse. A notice animals like cats and dogs don't seem to get dirty there, probably mostly because it's always exposed and isn't hidden between two buttocks.
So is it possible that caveman naturally had some odors down there or did he simply rinse it and was fine or is there something that I might be missing?