Rice sand is finely ground rice grains, but not as fine as rice powder. It creates a gentle exfoliant that is best kept dry until ready for use as rice will absorb water and not be as scrubby. This allows a dry scrub powder to be created and only hydrated moments before use to allow a preservative free product. If desired, it can be left on the face after use as a scrub to dry as a mask.
Make your own collection of clays and additives and store in an airtight container ready to go at a moments notice.