I'm surprised no one else has said this is a terrible idea.
Those socket attachments are chrome plated. Chrome, especially cheap chrome you are likely to find on your socket set, is not the same as stainless steel! Furthermore, some forms of chrome are really toxic.
http://en.wikipedia.org/wiki/Chromium_toxicity
Your wort probably has a pH in the 5.5 to 6.0 range. I don't know if that is enough to corrode your chrome plated metal or not because I don't know the details or science of corrosion of chrome plated steel. Will much corrosion occur in a week or two that you dry hop? Probably not. But my cheap chrome tools rust and corrode if I leave them and they get wet so ....
So I would err on the side of caution and remove those sockets from your wort.
If you need to weigh it down for some reason, I'd go for something more inert like clear glass or perhaps a stone.