There are several natural cleaners you probably already keep in your home. Lemons can help whiten. White damask napkins, linens, and even socks can be whitened on the stove: Fill a pot with water and a few slices of fresh lemon; bring the water to a boil. Turn off heat, add linens, and let soak for up to an hour; launder as usual. For extra brightening, spread them out in the sunlight to dry.