Rebatching, or hand milling, is a soapmaking technique used by hobbyists and artisan soapmakers. The commercial equivalent is French milling.

In rebatching, previously made cold process soap is shredded or diced finely and mixed with a liquid, into which the soap shreds begin to dissolve. It is then heated at a fairly low temperature until the mass is more or less homogeneous. When it becomes translucent and reaches a thick, gel-like consistency, it is spooned or piped into molds and allowed to harden.

Soapmakers frequently use rebatching as a way of adding substances that could not withstand the high temperatures or caustic chemical environment of cold process or hot processsoapmaking, such as certain essential oils (for example, those with a very low flash point). The choice of liquid affects the character of the finished soap; milk is frequently used to give the soap a smooth, creamy consistency. Rebatching can also be used as a way of salvaging soap that cracked, curdled or separated while being made. Triple milled soaps are often considered some of the finest true soaps in the market.

By definition of the process and creation of the "gel state", adding to a "liquid" and "rebatching", french milling cannot be physically accomplished with melt and pour soap. Calling melt and pour soap "french milled" is a deceptive marketing technique that I would not recommend.

Source:HomemadeBathProducts