I made shave soap for the first time to give as a gift this holiday season. I used songwind's recipe, substituting leather FO since the recipient likes the scent of leather and instead of crockpot I used the double boiler method. Here's what I learned: 1. KO is more reactive than Sodium Hydroxide and I had to pour it in very slowly 2. trace occurred very quickly 3. zap testing it, everything turned out fine but it wasn't very pleasant...like what tasting shaving cream would be like 4. my entire apartment now smells like brand new leather and i have the windows open to air it out! Not sure if HP is responsible for this since I used .25 oz of FO. It lathers nicely, even before the 24 hours needed for it to set and is slowly becoming a nice white color. I am using a ceramic mug and an Altoid tin, so far so good on both.