What kind of scenario do you have in mind, there? I can understand losing your pack, but your pockets?

Anyway, I don't currently have anything around my neck. I occasionally experiment with a couple of magnets on a loop of paracord inner strand. The magnets form a break-away clasp and are strong enough to pick up stuff. I don't want to put magnets in my pockets for fear of damaging my credit cards.

I suspect this is more fun and novelty than useful, though. If I dropped my car keys somewhere inaccessible, I might be better of improvising a hook from a paper clip and using that.

I have some stuff in a money-belt.