Ever noticed there's a line in the dishwasher soap dish? It says something like "fill here unless you have hard water."
It is likely that most of us are using too much dishwashing detergent. Try using less and see if your dishes still come clean. I usually squirt a bit in the neighboring reservoir that is released during the pre-washing stage. Every dishwasher is different so yours may not have this additional reservoir.
By reducing the amount of dish detergent you use, you could save money and reduce the residual toxins on your dishes. I've been to homes where I can taste the dishwashing detergent in my glass of water. Ewwww.
Just try it. Whad'ya got to loose?