For a cleaning machine, dishwashers can get pretty dirty inside. People have a lot of different ideas about how to use a dishwasher, and it shows in the stuff that remains when the dry cycle's done. The dishes may be clean, but there's food in the filter, a film on the walls and inner door, hard water stains on the metal parts and a general feeling that this isn't the machine you use daily. There are ways to clean a dishwasher so you'll feel more comfortable with using it to keep your family safe.
First, make sure your cleaning habits are on target. Getting the dishes into the dishwasher right after the meal makes it easier to get them really clean. Most people still think that rinsing them helps also, but there's a good reason why scraping excess food off is all you need to do. Modern dishwasher detergents use an enzyme process which cleans by working on the food particles rather than lifting them off as dish soap does. If there are no food particles to work on, the dishwasher doesn't do as good a job.
Over time, material will accumulate in the nooks and crannies of your dishwasher and cause odors and stains. Hard water can make even more stains. Regular cleaning and deodorizing with vinegar is simple and effective, helping to remove that vaguely offensive odor which dishwashers develop and also sanitize the interior. A bowl with a couple of cups of white vinegar sitting on the bottom rack will disperse this environmentally friendly cleaner when you run a cycle without detergent or dishes inside.
You may have already discovered how helpful baking soda is in cleaning the oven. In the dishwasher, it's useful for scrubbing but before you try that, simply sprinkle a cup of it over the bottom of the dishwasher tub and leave it overnight, then run a normal cycle. Use a toothbrush with baking soda paste to finish off any stubborn spots.
A complete dishwasher cleaning routine includes cleaning the filter if there is one, running a baking soda clean and scrubbing anywhere food material or deposits have accumulated and possibly steam cleaning to remove tough stains or stuck deposits. A vinegar cycle can freshen the inside, and then a thorough cleaning of the outside with eco-friendly products completes the process.
It can be tempting to run a bleach cycle for a more powerful cleaning and sanitizing process but do so with care. The risk of chemical interactions and lingering residue affecting those who eat and drink from the first cycle of dishes makes it a less desirable habit. Natural products and simple vinegar can do the job in most cases except for the most stubborn neglected interior. A cup of bleach run through a full cycle can whiten the interior, but it can also damage stainless steel interiors.
Just as you clean rugs, entryway floors and other heavily-used areas with a steam cleaner, it's a very effective and chemical-free way to tackle a stubborn dishwasher mess. The steam can loosen and remove built-up food particles, hard water stains, and other long-term deposits. Don't forget to use the steam on the door and gasket which are sure to need attention. A bit of wiping with paper towels removes the loosened material.
Depending on the type of exterior, you can use a natural soapy surface cleaner for colors or a glass cleaner product for stainless steel. Loosen dried material rather than scrubbing it off if possible to preserve the finish. Don't forget to clean inside handle areas and around the controls. Weekly cleaning and wiping spills immediately will make this a much easier job.
Many recent dishwasher models have filters to collect material washed off of plates and pots and pans, so it doesn't stay in the water as it gets sprayed onto the dishes during the wash cycle. It can get pretty nasty in the filter, so a monthly ritual of removing the filter from the bottom of the tub, rinsing out the accumulated debris and giving it a soapy washing will make a big difference. You'll probably identify a few places in your dishwasher which also seem to trap material, and a toothbrush can help displace anything which gets trapped there.
Don't forget that hard water can make it tougher for your dishwasher to do its job and also leave spots and stains on the interior. There are commercial products which can be used in addition to detergent to help prevent these problems. They aren't just for making your stemware come out sparkling clean.
Another way to prevent spots and stains from hard water is a water filter system. This can help reduce the amount of cleaning that you have to do to keep your dishwasher sparkling clean as well as improve your dishwashing results. If your hard water is causing buildup in showerheads and other plumbing around the house, you may want to consider a whole-house system. To simply address your dishwasher problems, you can get an under-counter system with replaceable cartridges.