I just want to make sure the advice wasn't based on the (antiquated WW2 era) concept that baddies make bombs with colourful wires and ticking wind-up analogue clocks. You'd be much better off using a mobile phone, a digital wristwatch, an electronic egg timer, you catch my drift. I agree that taking the battery out is not a bad idea, but not because it prevents the situation where one security person says to another "listen mate, it's ticking, do you think it's a bomb!"

Incidentally, would there not also be clothes in there to muffle the sound or is it a really loud ticker?!