Also sometimes referred to as soap nuts, of the Sapindus genus? Producing a fruit with high concentrations of saponin, a naturally-ocurring amphiphilic compound?
In other words, soap that grows on trees? Yes! It is a thing! You, my berry-eating comrades, do not have to fool with cooking down hardwood into ash and then soaking it into a toxic slurry in order to make soap to clean things up! You can actually just get that shit from a tree! There are trees for this specific thing!!!
Perhaps you'll be able to grow one in your climactic zone??? It will take a little more research than I'm willing to do for you while I'm drunk. Anyway, if you're going to use them, make sure you remove all the seeds, which will stain things, before you dry them for use.
NGL, they're pretty rad.
"The best time to plant a tree is twenty years ago." :100-com:
oh my god I never expected you to actually follow up holy shit comrade. Ordering them now and I will 100% update /c/gardening with my results. (Perhaps I can start the first Chapo Soapmaking Seed-trading Initiative)