Nice idea, doing it on "the planet known as Earth". :)

The Ixians and the Darlings have been working toward making soap in the CoffeeMUD rabbit-hole of the Galactic Milieu, there it takes basically fat and ash, so the Darlings have been working on animal husbandry to raise beef cattle (since for fat the game uses beef) while the Ixians keep campfires burning constantly in their city's central par to build stockpiles of ash.

Extra fun is that CoffeeMUD might not yet even be among the MUDs in which soap will actually make a difference in how much of your characters awake-time get consumed by bathing.

All in good time though, once lots of soap is available it will be time enough to look into making at actually useful if it turns out it is not already. :)