The spray arms in your dishwasher spray water to rinse and clean your dishes. When your dishes aren't as clean as they should be or there is a film of soap left on them, it might be due to blockages on the spray arms. Cleaning clogged jets in the dishwasher spray arms is necessary to open up the blocked passageways. It is not necessary to remove the spray arms from the dishwasher to clean them.
Turn off the power to the dishwasher. The circuit breaker is in your home electrical panels box. Open the dishwasher door and pull out the lower dish rack. Most lower dish racks simply pull straight out.
Fill a cleaning bucket with 1 tbsp liquid dish soap and hot water. Soak a rag in the soap mixture and wash the outside of the lower spray arm. Rotate the spray arm as you wash it, inspecting the holes along the sides. Remove pieces of dish labels that are stuck. If you notice clogged holes, squeeze the soapy water onto them and allow it to soak.
Pull the upper dish rack out as far as possible. Wash the upper spray arm just as you did the lower spray arm, if you have an upper spray arm. Some dishwashers have a spray arm attaching to the bottom of the upper dish rack.
Pour a cup of vinegar into a container. Dip an old toothbrush in the vinegar and scrub the jet holes of the spray arms. Vinegar softens mineral deposits that build up inside the holes. Scrub all of the spray arms in your dishwasher with the vinegar. Allow the vinegar to remain for 5 minutes.
Straighten a large paper clip. Insert the end of the paper clip into each spray arm jet hole. Work the paper clip in and out of each hole several times. The paper clip pierces through the softened mineral deposits and removes them.
Push the dish racks back into the dishwasher. Pour the remaining vinegar into the bottom of the dishwasher. Close the dishwasher door and turn on the circuit breaker to supply power to the dishwasher.
Run the empty dishwasher through a cleaning cycle. This allows the spray arms to flush out any remaining material inside the jet holes. The vinegar also removes soap scum in the dishwasher during the cleaning cycle.
If you choose to remove the spray arms, contact the manufacturer for instructions for your model.