Your survival plan should include a huge stock of toilet paper. Nonetheless, if you were faced with a long term situation in which the stock was used up, it would be good to know about toilet paper substitutes.
The problem is very basic. Personal hygiene is a high priority in survival situations; it’s good for both health and morale. Toilet paper is very convenient, but emergency preparation has to account for the likelihood that you’ll find yourself in a situation without it. Disposable wipes don’t count — they too will run out eventually. What we’re looking for is a permanent toilet paper substitute, and there is one that has worked during the entire history of man.