No, both at the same time: baking soda on the bottom of the dishwasher, glass of vinegar on the top rack. Mid-cycle, stop the dishwasher, open the door, wait 20 minutes and restart your machine, just like if you had forgotten to put something in it.
When you run the dishwasher, the water jets will mix the two ingredients. It's the same as when you add the soap, it gets dissolved and sprayed through the jets...
In addition to the vinegar and baking soda, try to use half of a lemon to fight the water stains. Apply the lemon directly to the stains, and then rinse...
You can try other cleaning elements such as bleach, borax, or hydrogen peroxide. Refer to "How to Remove Bathroom Mold" for instructions on trying these alternate methods.
