Realizing this is the Benchmark AHB2 thread (duh!), and that believers will believe and doubters doubt, I'll respectively withdraw. Start a thread, or return to one of many already created, to debate wires in audio (or any) circuits.
One last note: IIRC silver usually forms a sulfide, not an oxide, but it has been long since my inorganic chemistry classes... I only remember because I have to clean my trumpets now and then. The sulfide is slightly less conductive than pure silver. But, silver oxide forms an insulator, again IIRC. I am pretty sure about the latter as it is a big problem in the world of engineers when wire and relay connections fail due to silver tarnish (oxide or sulfide, whatever).