I got in a crafty mood one day several years ago, and decided to melt down all the leftover slivers and hotel mini-soaps. Just heating it in a frying pan didn't work because it tends to burn before it really melts into a liquid. And some of them had weird shit like oatmeal in them which scorched and left black bits.

So then I tried the pressure cooker. pieces of soap and a little water. It all went OK while heating up, but when I removed the weight, foam started coming out of the pressure valve. And then inside the pot, some of the big pieces had not melted. The little pieces were in the foam all over the pot.

I was planning to melt it and pour it into some cactus-shaped cast iron kitchen molds.. The plan was a failure, but I managed to press some of the softened mixture into the molds and got some black-speckled cactus soaps.

Bottom line: grate it up so the big pieces melt, add a little water, and melt it in the crockpot. Sounds like a plan. Post pictures, or make a howto video! 😆