If you're lucky enough to have a dishwasher, you probably use that sucker to clean everything (minus your good cooking knives), and maybe even to cook your food, too. However, dishwashers are not without their faults. Dishes can still come out spotty and even with chunks of food on them, which usually leads to some hand-washing afterward.
Instead of looking for an alternative dishwasher detergent to get the job done right the first time, try using a piece of lemon. Placing either a used lemon peel or an entire lemon wedge in with your dirty dishes on your normal cycle will leave your dishes spot-free and without any food residue. Plus, it'll leave a fresh lemony scent on everything. (Lemon waste is also a great way to clean your sink, garbage disposal, and cutting boards.)
In fact, it's not just lemons that work, but any citrus fruit with citric acid, e.g., limes, oranges, grapefruit, etc., and as safe to use in dishwashers with either plastic or stainless steel interiors. If your current dishwasher detergent contains citric acid already, don't worry—adding a little more will only help.
The citric acid in citrus is known to be an effective natural cleaning agent with a pH level 2 (along with vinegar), and is great at dissolving soap scum, removing hard water deposits, polishing, and disinfecting.
As an antibacterial substance, adding lemon to your dishwashing cycle will not only kill germs but also help to disinfect bacteria and even help keep limescale at bay (which builds up in dishwashers). Additionally, as a natural mild degreasing agent, lemon helps to remove all that clings to your dishes in order to make those items sparkle.
So slip a slice of lemon into your average dishwashing load, and you may discover your most difficult of stains disappear after one wash. That one dose of citric acid can dissolve all that you worry about, leaving your glasses and dishes cleaner than you would expect.