Just off Celebrity Beyond (12 day med cruise) - the 3 bags do NOT need to be put in at the same time. We purchased 2 individual bags and the individual "back home" package of 3 bags (2 cabins with our adult daughters). Pricing was a fair bit cheaper when purchased in advance. We received 5 tickets for laundry and used them sporadically throughout the cruise, shared between the 2 cabins. In the past, we would get laundry within 24 hours - this time it was closer to 36 or 48 hours.