The recipe for a cheap, environmentally safe, effective automatic dishwashing soap is really simple.
Mix equal measures of Borax (Twenty Mule Team or not) and Washing Soda (most likely Arm and Hammer) together. Label your container. It is environmentally friendly. That doesn’t mean that you want to eat it.
Use two tablespoons per load in the dishwasher. We keep a plastic spoon in the container and put two teaspoons in the closing dispenser and two in the open one.
Use white vinegar in the rinse aid dispenser. It is much cheaper than brand name rinse aids and it does just as good a job.
Yesterday, I used this combination to wash our cars. I used one tablespoon of the Borax/Soda mix with a few drops of Ivory dish soap in a bucket of water. I scrubbed the cars with that. Then I put some white vinegar in a used Pepsi bottle; attached it to the TerraCycle sprayer instead of the bottle of worm poop, and gave the cars a spot-free rinse.