Here is something to consider - if, in the future, you ever might want to get Global Entry and you don't declare the whiskey, and they find it, you will be banned for life from getting GE (which also gets you a trusted traveler #, which also gets you almost 100% domestic pre-check on any airline). In other words, I don't think it's worth it - find someone over 21 to carry it in for you in their luggage, even if it's another student over 21 going to a different U.S. airport you could pay them to send it to you by express mail. Global Entry (GE) is a very valuable benefit that you may really want in the future.