Listerine Menthol Mouthwash. | Thanks to its formula based on essential oils with fluoride, Listerine Menthol Mouthwash provides 24 hours of protection against plaque and long-lasting fresh breath peace of mind. Use hints: | Use mouthwash twice a day. Pour 20 ml (4 5 ml teaspoons) into a glass, rinse teeth and gen for 30 seconds and spit out. For children aged 6 to 12 years, the dose is 10 ml. About Listerine: | Listerine has been promoting oral hygiene since 1895 and its products eliminate bacteria that remain in the mouth after brushing. Listerine it has the seal of the Spanish Society of Periodontics and Osseointegration and is present in over 60 countries thanks to its special formula and all its dental practices, which have positioned it as one of the world leaders.