Years ago I used to take my croquet mallet as hand-baggage; and hand it over to the steward/ess.
But then Birmingham Airport stopped me 
They said it was a dangerous weapon?
After that episode, I bought a 2-stage, take-down rifle case for the mallet! (It was the right size!!)
The case then contained a mallet, a pair of flat-soled trainers, and a few odds-n-sods.
Every time I went to Jersey, I was stopped at the airport and asked if it was a gun!
I never locked the case! Made it easier to show what was inside

I even painted "Isle of Man Croquet" in big yellow letters on it
