Ever find a forgotten water bottle in a back seat or backpack? Instead of repurchasing, rescue reusable bottles with items you probably already have on hand. First, soak the bottle in warm water mixed with a little bit of bleach. Scrub it inside and out with a dish brush or toothbrush, then clean the mouthpiece with a cotton swab. Rinse thoroughly, add baking soda and hot water and then let the bottle sit overnight. Rinse with hot water and soap and dry completely before using.