Just returned in September from the Viking Century Sky. No inspection of luggage was performed so I doubt that they would notice. Suspect that this is a "don't ask - don't tell" situation! If you don't take it into the dining room who is to know?
A guy on my tennis team just returned last week. We spoke this morning and he said he and his wife had purchased (2) liters of Gin in CHicago at the duty free store. When he left he gave the remainder of one bottle to a cabin steward.
He said the beer was great , but wines are a 3 on a scale of 10.