I can't imagine me or my wife planning laundry time while on a cruise.
We use the ship's self serve laundry when available because we take only carry-on luggage with us. Having laundry available lets us cut down on a lot of things.
Plus, my husband works out for 90 minutes every day, and then washes his work-out clothes in the sink and hangs them up. If there are machines available, he doesn't have to do the sink thing every day.