To make homemade mildew cleaner, add several drops of grapefruit seed extract or tea tree oil to a spray bottle of vinegar, and spray the vinegar on the affected surfaces. Another option is to apply full-strength hydrogen peroxide to the mildew and then use a cloth to wipe the area clean. To remove mildew on clothing, soak the item in hot water and borax. If the clothing is color safe, wash it with chlorine bleach.
Chlorine bleach also removes mildew on hard surfaces, such as vinyl siding. Dilute 1/4 cup of bleach with 2 cups of water, apply it to the surface, and scrub the area. Rinse the surface with clean water after 15 minutes. To clean grout, mix equal parts water and bleach, and spray the cleaning solution onto the affected grout. After 15 minutes, scrub the grout, and rinse the area.
When cleaning hard-to-reach surfaces, soak several cotton balls in bleach, and place the cotton balls on the surface. Remove the cotton balls after several hours, and rinse the area with warm water. To clean fabric items with borax, mix 2 cups of borax into 2 quarts of hot water, stir well to dissolve the borax, and soak the item for several hours before washing it as usual.