Listerine Coolmint Antiseptic Mouthwash 500ml antiseptic mouthwash kills germs that cause bad breath, plaque & gingivitis. When used twice daily as part of regular oral hygiene, Listerin Cool Mint kills the germs that cause bad breath, plaque and gingivitis. Plaque is caused by germs in the mouth. Plaque build up may lead to gingivitis, an early form of gum disease. The symptoms of gingivitis are redness, swelling, and bleeding gums. Gum disease is a major cause of tooth loss. Your oral hygiene routine should include daily brushing, flossing and rinsing with Listerine Cool Mint and visiting your dentist every 6 months. Ever wondered why you need to incorporate mouthwash as part of your oral care routine? Brushing and flossing alone only reaches 25% of your mouth. Incorporating Listerine as your third step helps to kill germs in the remaining 75% of the mouth and can help reduce plaque to help provide that long-lasting fresh breath.