Well, I've had a few non-exploding fireworks (small rocket motors, really) loaded with 4Fg BP for three years... the entire motor had been soaked in Elmer's and then dried, and the endplug opposite the clay nozzle had been glued in too. No ignition yet.... :wink:
I think that maybe it was just a bunch of false information. I've got enough experience with BP to know that heat, static, and hard impact are the only things that will set it off.
How do I know these things? I'm a chemistry hobbiest, and I'm cheap - I make my own BP :grin: