Cruisers claim they were "degraded" for sneaking a washing machine onboard a Carnival ship
Would you ever think to try and smuggle a portable washing machine onto a cruise ship? Most likely not. Those on vacation typically don't want to think about doing household chores.
Even if you find yourself needing to wash a few articles of clothing, many ships have self-service laundromats in addition to valet laundry service, albeit the latter is more expensive.