Mouthwash is an antiseptic liquid oral hygiene product. It is used to prevent plaque buildup, gingivitis and bad breath. Piercers will often recommend as aftercare that people with new oral piercings gargle with mouthwash after eating, drinking and smoking in order to kill potentially harmful germs in the mouth, or when changing jewelry. Since most brands of mouthwash are very strong or contain alcohol, it may be suggested that the piercee dilute the mouthwash with water. Overuse of mouthwash should be avoided, as it can kill healing tissue as well as germs.