Dishwashers How heat, chemicals, and blasts of water combine to get out tough food stains Credit: Reviewed / Jonathan Chan Recommendations are independently chosen by Reviewed's editors. Purchases made through the links below may earn us and our publishing partners a commission. Understanding how a dishwasher works is key to learning how to get dishes clean. Many people, according to the Internet, believe that dishwashers fill to the brim with water, making a swimming pool for dirty dishes.