OK, instead of using hot nitric acid to dissolve old fine silver jewelry, would it work to just hang the cleaned jewelry in a solution of copper nitrate and use it as an anode? The copper would plate out on the cathode, and the silver would go into solution, right? What I'm worried about is that an oxide layer might coat the silver and stop the process. Is this method feasable, or do I need pure nitric acid? Mine's contaminated with hydrochloric that I'm too lazy to remove.

No, silver will preferentially plate out of solution at the cathode as it dissolves at the anode. The only thing limiting that would be the rate at which silver ions reach the cathode since ions don't magically teleport through solution.

I suppose I should have been more descriptive. The cathode would sit in cupric nitrate solution, and the silver would hang in sodium nitrate solution. The solutions would be connected by a salt bridge also containing sodium nitrate. As the cell runs, sodium ions in the anode solution should be replaced by silver ions, and the copper ions in the cathode solution should be replaced by sodium ions as they plate out. The reason I would use copper nitrate is that I don't want hydrogen to get reduced, lest a small amount of hydroxide ions find their way through the salt bridge and coat the silver anode with insoluble silver hydroxide. Any other people who think this process would work? It does not work with dissolving aluminum instead of silver, by the way; the aluminum just gets coated with oxide and the cell looses current.

I'm still watching for responses. (Just clarifying that this thread is not old.)