C, a while back (a few years) you packed BB's in those little party poppers, which we tied fishing wire fairly tight to, and booby trapped a whole area. Those worked pretty damn well.
They functioned flawlessly. The problem lies in whether or not they will be set off. In a large field, the odds are that they won't be.
At a field like Southwest, it's much more likely.
David, Matt P and I made a few boxes full of those devices for a BT a couple years ago. We tried different things, but the flour and BBs worked best. I told Mikey about them and he made some for the FEB game.