AFAIK you will have to use difficult to get *iron*wool rather than usual steelwool as you can buy easily in your local home improvement store. I have been told, using ironwool is a rather messy operation. The better way seems to be using sodium dithionite. Use 2 tablespoons per litre and put the (open!) containment in the garden far away from noses for some days. It will outgas hydrogen sulfide. After the reaction has finished the metallic silver particles sink down to the bottom of the containment and the liquid can be siphoned off with a small tube.