Pour 1 cup of Baking Soda into the dishwasher and run it through the rinse cycle. It will help get rid of some of the grime that collects on the inside of the machine, as well as freshen the smell of the dishwasher.
Baking Soda Detergent
Mix together 1 1/2 Tablespoons of Baking Soda with 2 Tablespoons of Borax. Use in place of automatic dishwasher detergent.
Or sprinkle baking soda on top of dirty dishes after they are loaded, but before they are washed. Make sure some of the baking soda is sprinkled in the bottom of the machine. The baking soda will serve as detergent during the first wash, leaving you to only add the detergent for the second wash.