Castile soap is made through the same saponification process as the natural soap bars the rest of us use. I just looked up the ingredients for the Dr. Bronner's Peppermint: Water, Organic Coconut Oil*, Potassium Hydroxide**, Organic Olive Oil*, Mentha Arvensis*, Organic Hemp Oil, Organic Jojoba Oil, Organic Peppermint Oil*, Citric Acid, Tocopherol

I'm assuming Potassium Hydroxide (potash) serves the same purpose as sodium hydroxide (lye.)
3a (Corkicelli), highlighted, fine, low porosity

HGs: Anything Sevi; Curly Kinks Satin Roots, Curlycue ReNew and Coil Jam; homemade FSG and okra gel; soap bars; UFD Curly Magic; Botanical Spirits Jellies, CJ Repair Me, Aloe Fix