A soap substitute refers to detergents or cleansing creams, other than soap, for cleaning the skin, especially removing greasy films or glandular exudates. Soap substitutes can be made from a variety of sources including plants with high saponin levels. Soap substitutes should not be confused with natural cleaning products which are cleaning agents for kitchen and house use.
Plants with high saponin levels are purported to contain saponins in sufficient quantities to produce lather (when mashed plant parts are beaten in water) and can be used either as is or in soap or shampoos.
References
Soap substitute Wikipedia(Text) CC BY-SA