If your towels smell musty or mildewed, wash your load of towels on the hot cycle and add 1 cup of vinegar to the load. Do not use detergent or anything (especially bleach – that can be super dangerous!)… just hot water and the vinegar. Let the washer do its job. Then, if they still smell a little bit, rewash with just hot water and 1/2 cup of baking soda. Again, no detergent, just baking soda and hot water. So easy!