is that even legal?
Yes and no; though its more likely “no”.
Unless you go through the processes, approval and licensIng for “drug” claims, the only thing you can legally claim about your soap is that it “cleans”.
When I first started making soap, I knew that I couldn’t make any cosmetic or drug claims about my soap, but I thought I could talk about the“benefits” of the ingredients, but even that is too fine a line, especially since the lye overpowers them during the saponification process so whether you are making soap with pig fat or some expensive oil that costs $100USD a gram...at the end what you have is a substance that cuts through dirt and grease...it “cleans”.
Right now I make four soaps...Regular, Goat Milk, Sea and Trades. The Sea Soap is for some friends who are commercial fishermen; its high in Coconut Oil so it works well with sea water. My Trades Soap contains pumice for extra cleaning power. I also have a Salt Soap that I have gotten some positive feedback on, but now I’m crossing into “cosmetic” territory and they wont be for sale until all my “I”s are dotted and my “T”s crossed.