Earlier quoted context omitted.
> it takes days to fill up the dishwasher to a level where running it isn't wasteful Dishwashers are much more efficient than you think -- more than handwashing. Just run it every day or two.
Having lived off-grid without running water, I know very precisely that I use slightly more than a gallon of water to hand wash my dishes. No way a dish-washer beats that.
That said, unless you live in a desert, or off-grid, 1-2 gallons of water a day has no real cost. E.g., I pay 0.7 cents/gal for the water and 2 cents/gal for the outgoing sewage.