My Whirlpool dishwasher gets food stuck in the water jets on a consistent basis. I have removed both upper and lower spinners and physically cleaned out each and I have also taken out the screen in the bottom and cleaned out underneth it. Another concern I have is We keep getting "sludge" buildup in the tub as well as in the jets and under the screen. I have also cleaned the washer out for this in the past also. It's a black greasy build up that keeps returning. Any thoughts? I'm thinking the grinder in the washer is no good and that the water is not getting hot enough by the washing machine.