Listerine Cool mint mouthwash. Did you know that brushing only cleans 60% of the surfaces of your teeth leaving plaque bacteria to grow in the hard to reach places in your mouth. Used twice a day Listerine Cool mint can kill up to 97% of germs left behind after brushing, reduce plaque by up to 56% more than brushing alone, provide fresh breath protection for up to 24 hour and help maintain healthy gums. 500ml. Always follow the usage instruction provided.