One day I was travelling from UK to Switzerland, the security officer at Gatwick airport check (with a kind of swab) all my electronic devices (mainly phone and camera chargers + cables) to see if it was in contact with any explosive materials.
Now I just remember that today I use a ring from a hand grenade to keep my home keys.
The ring is just the outside part which hold the pin and come from an exercise hand grenade but with the real explosive inside.
Just to mention this is not dangerous at all, it is just a metal part, which was one day on an exercise hand grenade. I just have it from my compulsory military service and it is not forbidden material.
My question is: is there any probability to detect some explosive (even it should not have been in contact) at the airport if they try to check my keys and what could be the consequences? Do you advise me not to travel with such a thing?