Unpleasant mouth odor is often the result of a coating on the tongue, not on the teeth. When you brush your teeth, don’t forget to brush your tongue as well. You can easily make an antiseptic mouthwash with tea-tree and peppermint essential oils that will not only freshen your breath but also fight against gum inflammation.Add ½ tsp. of tincture of myrrh and 1 drop each of tea-tree and peppermint oils to 1 cup warm water. Each time you brush your teeth, gargle with this solution afterward.