I think rules and regs aside for one second, and a little common sense to fill in the void. Speed freek makes a point.
Put out that fake cigarette.......
Stop that fake bomb from ticking......
Put away that fake combat knife...Oh Your a BBC Journo? It's okay then.
Please do not joke around trying to open the door at 35'000 feet. Passangers may think you are actually doing it. Sit down.
I aint' no crew commander, but if some idiot is gonna "joke around with a fake smoke, if it looks real enough, he can stuff it, and put it out. Ban him. What's next, fake hand grenades rolling down the aisle?