Mouthwash should only be used by children who are aged six or over. This is because younger children tend to swallow the mouthwash instead of spitting it out. Even those children who are over the age of six need some amount of supervision while they master the technique of gargling with the mouthwash. Most mouthwashes contain alcohol and fluoride, giving them a strong taste. While fluoride is necessary, too much of it causes damage to teeth that are still developing. However, mouthwash that is made for children contains very little alcohol and is available at all leading pharmacies and supermarkets.