Bowtarist, with this yucca we use, dig up the roots (I usually rinse the off a bit), pound them up with a hammer and the swish it around in the water. Ive used it to soap deer deer hides before braiding them. It was used for that a long time ago; helps break down any grease in the hide. I've also used it for washing my hair, but it doesn't lather up as well as commercial shampoo. It will clean your hair as well; just doesn't lather as much. It is great for scrubbing out pots and pans while you are camping. For the longest time I had tried to always use it freshly dug, but I've discovered that it can be dried also.
Curtis
Oh, you are supposed to be able to use it as a fish stun also, but I've not tried that one. It's not legal here in the States. CC