Now that would be interesting!!!(slightly OT)
Sounds like a challenge!
My submission: 20% neem, 10% laurel, 40% MCT or fractionated coconut/PKO, 10% dairy butter, 20% salvaged HL sunflower oil (used just a bit too long for deep-frying sea fish). Scented with a ton of chili pepper and cinnamon EO.
I wonder who would love such a bar of soap? On the other hand, it would quite certainly “surprise” any unprepared user, so it's not entirely wrong in this thread.
Off topic but I buy my laurel berry oil from a Turkish vendor and emailed him one time asking what percentage he likes best in his personal soap.
He said he uses laurel berry oil at 100 percent in the soap he makes and loves it. He also told me to try it.
So I did and it is great soap. Very nice lather and skin friendly with that laurel smell that I like personally. Overall it is very good stuff IMHO.
It is expensive to have it shipped all the way over here but maybe you can get it cheaper and try it at 100 percent in a few bars. You might like it.
ETA: Oh, I still have some bars after 3 years and they held up well and I use it mainly in the summer to relieve insect bites, poison ivy rash, etc.