No, that's not useful.
They are at school to learn.
They can watch movies at home.
I thought this for a very long time, and was absolutely shocked when one of my fellow NETs brought in a movie for them to watch AND THAT'S IT… And I definitely don't see the point in watching Korean movies… but one of my Korean co-teachers actually showed 'Sunny' in one of my classes-- and it was her idea. Basically, it's about keeping them quiet.
I've also come to realize that unless you have a super keen class, there's not much point in trying to force them to do anything learning-related at a certain time of year… which is fast-approaching and in my case already here for the third year students. They've already gotten used to not doing anything in class and have basically checked out… I've tried to get them to play games that are super fun and have always gotten a good result, but they still complain before sitting around doing nothing/talking/getting into trouble.
I'm showing 'Drag Me To Hell' to my second and third year students-- it's pretty far from a Christmas movie, but it's good because they like horror and there's no sex (the main couple don't even live together) or torture porn like the Saw movies they were watching last year-- it's PG-13. I actually couldn't get the subtitles to work for one of my problem classes and they were still paying attention, so that has to be a good thing-- one of them even asked 'YOU SHAMED ME! moiya?' so that's something of a victory.
In some cases, I'm handing out 'scavenger hunt' sheets and getting them to watch out for/identify certain actions/scenes in the movie… so if they see it they raise their hand and identify the scene… it's completely optional. It's not really so amazingly in-depth but it keeps them pacified… even though there was still something of a fight in my most notorious class today. On the other hand, I had a conversation with a few of them today, which wouldn't have happened otherwise.