When I attended school just outside Rochester, NY, our shop teacher conducted a gun safety class and we brought unloaded weapons (rifles) in to use for dry sighting and familiarization. He and my Dad arranged to take a bunch of us out to a local shooting range. Couldn't do that today.
Think about what you just said, “Couldn’t do that today”. Why not? In fact, it *could* be done soon, if not today, with just some changes to state laws, and telling teachers and administrators opposed to guns that while they may choose to not participate, they have no authority to block or interfere with what others do.
While they get little press, and no union representation, there are still a LOT of conservative teachers out there who would be willing to do this, if the states provided them protection from harassment from administrators and their peers.
Importantly, there are also a LOT of kids from families that would be all in favor of gun instruction and practice for their kids. And not just boys, either.