Depending on the quality of your water depends on what kind & how much dish soap to use. If you have hard water, you would want to use the maximum amount of liquid dish soap. If you have a water softener or soft water, you would want to use a small amount of powdered dish soap. Following these recommendations should prevent the soap film on the dishes. In order to clean the inside of your dishwasher, you can wipe it down with a sponge using a mixture of powdered dish soap & water to form a paste. Another procedure is; put 2 cups of white vinegar in a glass measuring cup, place the glass container on the bottom rack (upright) & let the dishwasher run through a complete cycle using the air-dry option. Be sure the unit is completely empty. Another procedure is to purchase a product called â€œdishwasher magicâ€ This is available at most grocery stores or Sears. Other helpful tips; be sure the rinse aid reservoir is full, run the hot water at the sink to purge the line of all cold water before starting the dishwasher.