Mix 3 tbsp. of white vinegar, 1 tsp. of borax and 2 cups of hot water in a spray bottle. Shake the bottle to dissolve the borax. Keeping mold off walls. Spray the solution on the bathroom walls and let it dry. This will kill any remaining mold spores, remove stale bathroom odors and prevent the future formation of mold. Spray your bathroom walls once a week with this solution.