I went to a Baptist school as a kid, and first thing after the morning bell, we'd stand and say the POA, and then we'd turn to the only other flag in the room, and sing "Onward Christian Solder". As that was a few decades ago, I would not expect that to be the norm.
Also, a quick note to Dean Ferguson of that Baptist school: Maybe go drink some drain cleaner and then throw yourself off a bridge, you fucken tool.
For the full weirdness, though, it used to be that movie theaters on U.S. military bases would play the National Anthem (along with inspiring images of 'Merican jets flying, Marines doin [whatever], USN ships racing through the sea, etc.) prior to showing the movie. All of which struck me as more than a little strange.