I use over the counter 3% hydrogen peroxide as a mouthwash, but have always disliked the aftertaste. I purchased a bottle of peppermint oil from the baking section of my local market, and put one tablespoon in an eight ounce bottle of 3% hydrogen peroxide. Mouth feels very clean (and now minty fresh, too!) Others may like to add their favorite flavors, increasing or decreasing the measurement according to taste. Make sure to GENTLY shake your bottle before opening to keep peppermint oil evenly distributed, and keep your mouthwash in an opaque bottle (I use the same brown bottle purchased at the dollar store). Refrigerate if your bathroom is very warm, and keep bottle out of direct sunlight.