Dishwasher additives claim they can help, including Finish Power Up. Consumer Reports tried Finish Power Up according to the manufacturer’s instructions, putting it in the prewash dispenser. But dispenser sizes vary, and the dishwasher Consumer Reports used didn’t hold enough to get the job done. There was not much difference before and after washing with Finish Power Up. Then testers used the alternate instructions, which say to put the Finish directly into the machine. That time the dishes came out looking clean.
Next up—Glisten Dishwasher Cleaner and Hardspot Remover, which comes in premeasured packets. It removed the residue after two cycles.
Then there is Lemi Shine Original. Its instructions say to use it to clean the machine first—then with the dishes. Though you may have to experiment with how much to use, it also worked.
In fact all three products ultimately worked. Consumer Reports says the Lemi was the least expensive and the best value.
Consumer Reports cautions not to use Finish Power Up or Lemi Shine with a detergent that contains bleach. Both are acidic and may produce toxic gases if mixed with bleach.