One of my earliest experiments is with neem and grapeseed. In fact I've posted in the recipe feedback section and got good advice over there.
I went ahead and made with what little neem I had, which came to a little less than 6% and 15% grapeseed. My son, who the soap was for, has visibly less blackheads and his pimples, while not eliminated completely, are less and not huge n red like they used to be. This is after continuously using the soap for about two weeks? It's been a little more than a month of cure, but the smell is still there but not as bad as when it was in the slow cooker, it's more of an earthy smell now than burnt garlic.
I know the poster intended the soap for horses, but I just wanted to share how potent even a little of neem is, in terms of benefits and smell haha