As nasty as it sounds, if my (single, bachelor) Father didn't have a dishwasher, he'd be wasting more water than you can imagine, cleaning up what happens when dishes sit for a week or more.
Instead, he puts the dishes in the dish washer, which apparently inhibits mold growth, or at least hides it so no one notices...
Once he's getting low on dishes, he adds soap and turns the machine on, and it cleans/sanitizes his dishes. When they come out, they look just as good as new.
It has a built in water heater, so it's not piped to the hot water supply in the house.