There is an easy cleaning solution for dishwashers that came from products for outer space. One drink, Tang, was made for the men in space. Use an entire container of Tang or even a generic or store brand of the same, and run your dishwasher without any dishes or soap.
Just use the tang type dry crystals. You can put some in the soap dispenser if you want and pour the rest in the bottom of the appliance. Run the entire cycle it would normally run, except the dry cycle is not necessary.
The citrus is refreshing and the dishwasher should be clean. If it was extra stained, you might want to run a second load the same way. I never had to do mine twice, however. Your dishwasher will smell and look so clean, and you can say that it’s from out of this world. This space age tech cleans your dishwasher like new!