I teach at a junior high school. From my experience teaching restless and hyperactive teenagers, I can say that getting them to stay back after school to discuss what they consider high-brow stuff like Bitcoin is a really bad idea. Kids that age like gaming. Someone else mentioned Zebedee, which I think may work. Getting them to form their own groups and play against each other may get them excited about sats in the first place. After all, their competitive spirit is evoked. Coin Hunt World isn’t available in my country, but I would think it would become a hit among your students. The whole notion of moving around and answering trivia questions and earning some sats should appeal to them.
Another thing I know teenagers like is self-expression. With the de-influencing trend going viral these days, they like to take 0.5 photos and post TikTok videos and whatnot. Maybe allow them to use their phones to produce videos and photos related to Bitcoin and upload them on their social media. You can ask them something as innocuous as “make an ELI5 video on Stacker News” so that they are compelled to do research while making their product. They are addicted to likes and views. Once they receive attention from their social networks, I guarantee you that they will be hooked on creating more content about Bitcoin.
Good luck!