"Natural mouthwash" usually means a rinse made with plant-derived, mineral, or simpler ingredients instead of a conventional formula built around alcohol, strong antiseptics, artificial dyes, or opaque flavor systems. The phrase can be useful for shopping. It is not a standardized dental efficacy claim.
That matters.
A clean mouthwash label should make it easy to see what is inside and why it is there. Look for details such as alcohol-free status, fluoride-free status, herbal extracts, essential oils, sweeteners like xylitol, preservatives, and acidity. If a rinse carries an ADA Seal, that seal has a specific review process, and the American Dental Association explains that accepted products must meet its criteria for safety and efficacy.