A sea salt mouth rinse kit includes: a bottle with a fill line； and a plurality of packets, each containing a predetermined quantity of pure sea salt. In a water filling step, a user fills the bottle with water to the fill line, such that it then contains a predetermined volume of water, at a tepid or room temperature. In a salt adding step, the user empties one of the packets into the bottle. The predetermined quantity of pure sea salt fully dissolves and closely approaches full saturation, without precipitating out, in the predetermined volume of water at a water pressure and pH both falling within normal ranges for distilled water consumed by humans. A user selectively rinses with the water through an opening in the bottle, and a cap selectively securely closes and seals the opening.
