You could inquart and leech with sulfuric acid.
Either silver or copper would work. But, to use concentrated, you would need to use silver. There was actually quite a bit of good old information on 911metallurgist about this, including ways of reducing the silver sulfide back to silver metal.
I have never used this methodology, but I have been reading up on it quite a bit after I first saw mention of it. I believe the reason why its not used more often is because of the dangers of hot sulfuric, and the silver sulfide can be a pain, especially silver bisulfide.(silver sulfide are yellow crystals, the bisulfide ones are small white mushy ones)
The way they would prevent the latter from forming is by decanting off the concentrated sulfuric (after leeching) and running steam over it until it reached 60% concentration.
You could also use copper I would think, but you would then need to start your leech with a dilute concentration of sulfuric... So, that may be better, but I dont have any other insight beyond that...I will keep reading up on it though to see if there are any other points of interest on the subject.