In the article, Cold Process Soap Making, Melt And Pour And Rebatching Soap - Easy As Pie! discusses the differences between CP, M&P and Rebatched Soap. There were a few new things that I learned from the article.
Cold process soap is known for its hard, long lasting quality. Depending on the oils used, the bar can have great lather (coconut oil has excellent lathering properties), be incredibly mild (olive oil is renowned for its gentle qualities) or be very moisturizing (with the addition of oils, such as shea and cocoa butter or hemp oil). The article describes on how to make soap by this method.
Melt and Pour:
That the artistry of melt and pour is called "Soap Casting". I have not heard that term used in describing M&P as much as "Soap Crafting".
Rebatching is another form of cold process soapmaking. You make your cold process soap from scratch, grate it up, place it over a heat source in a kettle, (or your microwave) with a little liquid (water works very well), and the mixture melts down into a mushy mess to which you add herbs or colorants and fragrances. This method is often used to preserve the scent or the healing properties of some essential oils.
I never have created by the rebatched method, but the only way I have seen it described was doing it in a double boiler. But according to the article, there is the BOIL IN BAG METHOD which is supposed be one of the most foolproof methods the author has found for rebatching soaps. In the article, this method is described on how to make rebatched soap by this method. If you have not had much success with rebatch soap, you may want to try it this way.