Well, sometimes when the FA takes my jacket and ask me if anything left in, I say "just one million dollar, dont worry about it".
Funny thing is that it always make to CX FA smile but then recently on a JAL plane, the FA took it more seriously and was not so sure of what to do with my jacket, I had to confirm clearly it was a joke...

Of course one has to be insane to say anything even remotely sounding as "bomb" while on a plane...