Tip: Cleaning Dishwasher Stains
If you have a lot of iron in your water, over time the interior of your dishwasher will develop brown stains.
One option, instead of scrubbing, is to fill the dishwasher
soap dispenser with Tang or a similar powdered citrus juice drink.
Run the wash cycle, then crack the door open and let the machine sit for an hour. Next, close the door and complete the cycles. The dirty brown interior should clean up to look as good as new.
Hint: No dishes should be in the dishwasher when doing this.
-- Tips courtesy of HomeAdvisor.com