Mix 1 cup white vinegar, 1 cup warm water, and 1 tbsp. baking soda in a container. Dip a cloth into the solution.
Wring out the cloth, and use it to wipe the inner and outer surfaces of the washer and dryer. Clean around the seals near the doors of the appliances as well, as odors sometimes linger in these areas. Use a brush dipped in the cleaning solution to reach areas such as the fabric softener reservoir.
Allow the washer and dryer to air-dry.
Add 1 cup of white vinegar to your washer, and run it through its regular cycle.