My dishwasher is not cleaning the pots? What makes a detergent work, which is best for my dishwasher

No matter which detergent you use they are made up of the following ingredients and its the combination of these ingredients that make some detergents better than others.

1) Oxygen Bleach, which removes stains, including tea and coffee and also removes coloured food residues.

2) Surfactants, specifically to remove greasy food  left overs from the crockery, surfactants actually surround the grease and lift it from the crockery and then suspend it in the water so it can't redeposit onto the crockery.

If you have hard water, it will make it more difficult for the surfactants to work efficiently, however the next ingredient will help to solve that problem.

3) Builders, specially designed to remove water hardness allowing surfactants and the other ingredients to work effectively.

4) Enzymes, there are different types of enzymes each effective on different types of food stains and residues,  very effective on very tough stains and food leftovers. By using a combination of enzymes the best results can be obtained.

5) Polymers, once the other ingredients have removed the food and stains from the crockery the polymers suspend the soiling in the water, preventing redepositing of the food or stains. Polymers also assist it making the pots shine at the end of the wash.

6) Perfumes, for that fresh clean smell at the end of cycle, not just any old perfume, but a blend of several to appeal to you the consumer.

As a general rule, the more you pay for the dishwasher detergent the better quality ingredients and more combinations of ingredients will have been used. Top brands such as Fairy will guard their ingredient recipes very carefully, and if they make detergent for anyone else you can bet it's not going to be as good as their own brand.

You always get what you pay for, quality costs a little more money.