How to Make Soap from Wood Ashes, Cooking with Doctor Chill: Although he uses modern means, he explains what is happening chemically and how things work together.

How to Make Yucca Soap, Corporals Corner: Starts from identifying and harvesting yucca through finished soap.

Desert Survival Soap, Yucca Root and Creosote, Junkyard Fox: Another perspective on yucca soap and using creosote as a scrub and anti-microbial.