Mouth rinse or mouthwash…is a product used for oral hygiene. Antiseptic and anti-plaque mouth rinse claims to kill the germs that cause plaque, gingivitis, and bad breath. Anti-cavity mouth rinse uses fluoride to protect against tooth decay. However, it is generally agreed that the use of mouthwash does not eliminate the need for both brushing and flossing.

Common use involves rinsing the mouth with about 20 ml (2/3 fl oz) of mouthwash two times a day after brushing. The mouthwash is typically swished or gargled for about half a minute and then spat out.

Active ingredients in commercial brands of mouthwash can include thymol, eucalyptol, hexetidine, methyl salicylate, menthol, chlorhexidine gluconate, benzalkonium chloride, cetylpyridinium chloride, methylparaben, hydrogen peroxide and sometimes fluoride, enzymes and calcium. Ingredients also include water, sweeteners such as sorbitol and sodium saccharine, and a significant amount of alcohol (around 20%). Because of the alcohol content, it is possible to fail a breathalyzer test after rinsing. Many newer brands are alcohol-free.

A salt mouthwash is a home treatment for mouth infections and/or injuries, or post extraction, and is made by dissolving a teaspoon of salt in a cup of warm water. Plain (dilute) hydrogen peroxide is another common mouthwash.