Bought this washer shortly after moving in 15 years ago, back when the well was only 22 feet deep and the water got more and more orange from rust till we put in a proper deep one (until then, we had no idea it was so shallow.) Though I have cleaned the dishwasher a couple of times, attempting to get the rust stains out, and cleaned the food trap, I never really researched how to do it properly.
Today so far, I have taken a pointy object to unplug the holes in the washer arm. The ones on the ends were scaled over, and also got lots of hair and gunk out of the interior ends. Not easy as I couldn't actually remove the arm to do it, but after a couple of rinse cycles it seems much better.
I scrubbed a little of the rust stains I could reach with a plastic sponge and vinegar but now have 2 cups of vinegar on the bottom and another glass cup full of vinegar in the top rack to which I added a bunch of baking soda. The foaming action was impressive. Now it's running on the regular cycle for a bit till I'm supposed to shut it off for 20 minutes and then let it finish. I've done that, first I just slightly opened the door, then I thought, what if it allows leakage? So I close it and put it on one hour delay. Now I can go walk the dogs and turn it back on when I get back.
Hope this makes a difference in cleaning the dishes. Sometimes the glasses get bits of sandy crap stuck inside. We shall see.