My dishwasher is actually pretty good, about a year old: KitchenAid.... my washer is a front loading Sears... that was a mistake. I was familiar with European front loading machines which clean clothes like nothing I’d seen. I now know the difference... the Euro machines HEAT the water to a higher temp. My grandmother can set hers to boil for whites, they come out spotless. My American version that’s energy efficient... meh and you’re right, they need more water. Online I found some tips... people are pouring extra water into the pre wash container in the drawer where you put detergent.
You have to buy a washer with the sanitary cycle. I still don’t know if they get as hot as the “kochwasser” cycle in Europe but those washers do heat the water. Still, ours don’t “waste” as much water here so they don’t get the clothes as clean. Try putting a big towel in, soaked full of water.