Here is a demonstration of some traditional Native American backcountry know-how on making soap from yucca (Yucca whipplei). It is, admittedly, esoteric knowledge that is obsolete in the current age of abundance where innumerable soap varieties are available in countless stores. It is a novelty rather than a necessity.
Though a chore to make, yucca soap works remarkably well and a thick, slimy lather quickly foams up. Of course, make sure not to be washing up in the creek upstream from people who may be using the water down the canyon!
I shot the video with an iPhone, hence the poor quality. I couldn’t get my other camera to work for some reason.
Jack Elliott's Santa Barbara Adventure 
It is a natural product, but still polutes the water? I suggest we never lather up in any stream or lake.
Interesting video.
It doesn’t pollute the water any more than rubbing your hands together with mud and washing them off in a stream or walking through a stream with bare feet and stirring up sediment. Ideally, one should never add anything to a stream. Typically, I cart water from a creek for use away from the streambed.
In fact, I would suggest that swimming in a stream might pollute it more due to the fact that the water is washing over every little orifice of the body and such. . .
I know what you mean, our water is precious, we need to fight to keep it for drinking.
Thank you, Maggie. I appreciate your thoughts and your desire to keep the environment as pristine as possible.
After posting this video and reading Maggie’s comment, with which I agree and appreciate, I thought I should note that the reason I washed in the creek was that it made making the video a little easier. Perhaps I was foolish for doing so. I am very conscientious of my impact on the environment and usually always strive to leave as little a trace of my presence as possible. I don’t even like seeing footprints when I’m in the backcountry so the idea of fouling watersheds is beyond the pale. This is something that I was taught as a child by my dad and practice as a matter of routine.
Yucca soap…that is interesting.