Now I don't know your opinion on any of this, but I certainly had my reservations about bringing alcohol to school. Not only would it be my place of employment for a year (now going on two), but it's also a place full of little kids. I just didn't feel comfortable with the whole concept of showing up with some whiskey for the school principal the first day. I certainly wouldn't do that in any other workplace, so why would I do it in a foreign school of all places? It sounded a little absurd to me, and it really is.
There are many other things you could consider bringing. I've heard people brought Girl Scout cookies. This is something I never even thought of but it's a really great idea. A country like Korea doesn't have Girl Scouts, so this would be a great, unique gift from the states. Something that would conjure up a conversation too. Someone on my YouTube channel also mentioned bringing a family crest. Also a GREAT idea. These crests are very much foreign to most Asian cultures and would be a great ice breaker and something the teachers would otherwise not be able to get other than through a foreign teacher!
I personally opted to not bring anything. Sounds like a bit of a bail out, I know. My thinking was to wait until I got to know who my co-workers were first and then buy them something that I knew they would probably like. And that's what I did. It worked out great. I just waited for one of the holidays to roll around and I went out and got something locally or had my family send me something.
Whatever you go with, think long and hard about bringing a bottle of booze with you. Though it may cause some laughter, it could potentially shine a strange or negative light on you. Be a little more creative and I think your first impression will be more meaningful in the long run.