i started making soap a little while after getting my tm, and the thought did run through my head to use the tm to make it, but i think i prefer to make 2.5 kg batches of soap, and that won't fit into the tm. size aside, i think raw soap is so caustic it would be awful to ruin the tm in any way with a little splatter of raw soap.
btw, there is nothing which compares to homemade soap - i is so nice to use i never want to ever buy commercial soap again.