The advantage here is that EVERYTHING sets off the metal detector, and none of it is really a weapon--unless you take off one of the gloves and throw it. There's also the added advantage that if someone else in the building goes postal, you have some added protection.
Could that be what all this metal detecting is all about? Does Bloomy have something planned for us that gives him reason to expect one or more of us to go postal??? Hmmmm.