SLSa (Sodium Lauryl Sulfoacetate)
This white powder is great for lather and bubbles. "Coarse" will not need to be ground but is called course since it is just slightly bigger of a particle size than the ultra-fine airborne SLSa. Coarse is the ideal SLSa for less mess.
Not so be confused with SLS (Sodium Lauryl Sulfate) which is a much harsher surfactant.
You can add this to bath bombs and bath salts to give them some added foam or use them in bubble bars.
Used in powders, cream soaps and shampoos, as well as in melt and pour soaps. Use from 1 to 3% as a first attempt. We found that we liked the lower rates better than higher rates. This product is even recommended to be used at 50%.
Although course in comparison to a fine powder is still an irritant, so it is recommended to wear a mask when using it.