I think somebody suggested this as a way to close a tailrotor chain bracelet; I tried it and it worked great.

Stopped at a local tattoo / piercing parlor, they had one of those little barbell-shaped studs, it fits great. A straight bar about 3/8 inch long and 1/16 inch thick between the balls on either end, just fits the chain.

Not that I might look like a cop or anything, but I think I heard all the toilets in the place flushing as I opened the front door...