On the top rack of your dishwasher, place a dishwasher-safe cup filled with white vinegar. Set your dishwasher at the hottest temperature possible and run through an entire cycle; including the drying cycle. Make sure your dishwasher is empty except for the vinegar.
The vinegar’s purpose is to wash away any grease, dirt or grim and removes any loose particles and simultaneously sanitizes your dishwasher and helps to remove any moldy or musty smells.
I read that if you don’t have any white vinegar you can use a packet of unsweetened lemonade mix in the soap cup, but that you should be sure not to use any other flavor as it can stain your dishwasher. I’m not so sure I trust that method, but if you know it works, you can let me know in the comments. I would love to know if that helped your dishwasher.
Tip: Run the water in your sink until it runs hot. Then start your dishwasher. That way, your dishwasher will start the cycle with water that is already hot.
After you have run your dishwasher with the vinegar wash, you can then sprinkle a cupful of baking soda around the bottom of your dishwasher (under the dish rack) and run your dishwasher again on the short but complete cycle on the hottest water setting. This step helps to freshen, clean and brighten your dishwasher and also removes any stains.
If you still notice any mold or mildew problems after these steps, you can pour 1/2 cup to 1 cup of bleach to the bottom of the washer and run a hot full cycle.
****NOTE Do Not use bleach in your dishwasher if you have a stainless steel interior!!!! *****