Lab trials are always a good idea before making additions to wine lots. This is especially true with copper additions as you want to make sure your addition is going to have the desired effect.
Foul-smelling sulfur compounds can be either sulfides or disulfides, and copper alone is only effective against sulfides. If you prepare a copper trial and you don't see any improvement, then your wine has a disulfide problem and you'll need to add Ascorbic acid with your copper and wait several months for the stink to go away. If you see your copper trial improving the wine, then you have caught your sulfide problem in time.