Soak Spray Arms in White Vinegar
Mechanically removing scale or bits of food from the holes in the spray arms will help transform a dishwasher from not cleaning to one that works a lot better.
Since the arms are already removed you can soak them in a bath of white vinegar to clean them even more. White vinegar will naturally breakdown old dishwasher soap and scale buildup.
You can do this one of two ways.
The first option is to place the arms on a four-sided cookie sheet and add the white vinegar. The second option is to put the spray arms in a clean kitchen sink and soak them with vinegar.
In my video I put duck tape over the holes of the arms, but this didn’t work all that well. At least you can learn from my bone-headed ideas and save some time.