Apparently, they do correlate. When open interest skyrockets it's mostly because of the increased net short position of large commercials.
That makes life simpler, you just have to look at the open interest which is given each week on the 'GotGoldReport' site, and you will automatically know whether net short positions went up or not.
If open interest is high, you can be sure that silver will sell off.
|Chart 1: Open Interest Silver|
|Chart 2: LCNS Net Short Positions Silver|