If you're in a hard water area and wiping with detergent doesn't remove all the film, run a normal cycle with 2 cups of white vinegar in an upright glass on the lower rack. Salatino advises turning off the "heated dry" option during the cycle.
There also are commercial cleaners marketed especially for mineral buildup in dishwashers.
Consumer Reports recommends replacing worn or rusted dish racks, and using care when loading dishes and silverware so you don't damage spray arms. Inspect the arms to make sure they aren't clogged with debris, which could affect water pressure. Use pipe cleaners to dislodge blockages.
For cleaning the outside of your dishwasher, Salatino says all you need is a soft, damp cloth or sponge and mild detergent. If you've got a stainless steel cover, you'll need a special cleanser.
Phosphates, which help control water hardness, were eliminated from dishwater detergents a few years ago over pollution concerns. Since then, some consumers have complained that dishes don't seem as clean.
Lucinda Ottusch, with Whirlpool's Institute of Kitchen Science, says one mistake people make is buying cheap detergent. She says the all-in-one packets by name-brand companies really do help your dishwasher perform best.
She also recommends a rinse aid, which promotes drying by allowing the water to sheet off dishes.
Loading your dishwasher properly also can aid cleaning. Find tips at http://www.instituteofkitchenscience.com/kitchen-101/dishwashers
And, you don't have to wait until the dishwasher is full to run a cycle. Ottusch says many newer models sense the size of a load and how dirty the dishes are, and work accordingly.
"Running the dishwasher takes very little water and energy, and waiting until it is packed full of dishes can compromise cleaning performance," she says.