Sorry if this has ben done before, but I could not find it on here anywhere. I wanted to put a stick soap in my Rolls Razors shaving stick which came empty, so I cut off the top & bottom of a old cylindrical shampoo bottle which just fitted over the shaving stick screw base. I purchased a 1 kg tub of Stephensons melt & pour soap from Amazon, price £11.49. I melted some of it in a large mug, ( 1 min in the microwave on 600 ) added my chosen fragrances, poured it & let it set over night ( Very Hot ) & this is how it turned out.
Thanks for that, I thought is must have been covered at some point. At least I know where it is now. The reason I posted it, it is so easy to get it wrong, I purchased a block of soap from a shop on Mull it Scotland on a resent trip up there & could not wait to get home & make my new shaving stick, chopped the soap up, stuck it in a large mug, wacked it in the microwave, opened the door & the microwave was full of giant red hot marshmallows. I had to wait for it to cool down. It stuck like S**t to a blanket & then it took me 2 hours to clean the microwave with a wallpaper scraper & scourer. Lesson learned, but I do have a very clean microwave.
Note, tallow soap will not melt in the microwave. And if you do microwave a melt-and-pour soap, 10 second bursts are the way to do it.
The last time that I ground up two different soaps and combined them, I did it cold. There was also some coconut oil involved.