Suffering from blisters? Breaking in your new shoes can leave painful blisters on your heels. For quick relief, moisten a cotton ball with a minty antibacterial mouthwash then gently dab the spot. It may sting if the blister has popped but it will go away quickly. Repeat the process as needed until the blister disappears. Mouthwash contains a powerful antiseptic that will shorten healing time by a couple of days.