Yes, the duty free in MBJ has the sealed bags and you can request your item(s) to be sealed. I don't understand why they would not be permitted to be carried on through. That's the whole idea. Why would you request these bags if at your next stop they have to go into your checked bags. Hmm. Brown bottles not acceptable. That's a new one I've never heard of before. New rule, I guess. The Chinaman in Times Square has the next best price to Airport Duty Free.