Grapefruit seed extract, along with essential oils such as clove, lavender, and tea tree oil, have antiseptic properties and operate as natural fungicides. If you're dealing with mold when cleaning a bathroom or kitchen, try adding one to two teaspoons of essential oil to two cups of water in a spray bottle. You can also mix 20 drops of grapefruit seed extract with one quart of water. Not sure where to buy essential oils or grapefruit seed extract? Check here for a variety of oils, or here for grapefruit seed extract.