I used Rose Clay in MP for a facial bar once but I had to cut back significantly as my bar shrunk in a week. Its definitely trial and error. My experience was less is more with clay in MP. Good luck!
Its a shame you had this experience. I make MP soaps and I have been a "neighbor" to CP/HP soap makers many times at craft/art fairs and I always make it a point to say hello to my fellow crafter. I've never had a CP/HP soap maker feel upset that I'm their neighbor. The last craft fair I...
I also use the pyrex cup in my microwave. I tried using the plastic cheaper measuring pitchers from the dollar store but they didn't do well and melted.