I have been through a fair number of speaker cables - many were upper end Audioquest - and then one day bought and connectored some "Western Electric" cloth covered tinned copper 36 strand 10 gauge wire on Ebay and was astonished by how good it sounded on my tube amp system running Klipsch Cornwall 4's. Some in the Japanese audiophile community swear by this kind of wire for tube amps and horn speakers.
This wire had been "burned in" for about 40 years at a telephone central office, and I seriously doubt it was "OCC" copper. It had been subjected to 40-50 years of 48-175 d/c volts daily. Perhaps a case could be made for such wire having been somehow annealed to having fewer grain boundaries during this journey, but I doubt anyone would give this credence without analysis at the atomic level.
To further incite the wrath of the cranky audiophile community I also recently did some bi-wiring on this same system with some 16ga wire of the same "Western Electric" pedigree by making some spaded jumper cables with the stuff and running them from the bass speaker terminals to the treble connections. According to some internet experts this should make absolutely no difference. This was done to, theoretically, reduce some of the energy going into the tweeter relative to what was going into the woofer. I waited until after component burn-in to do this because I had learned that fiddling with the system before components had revealed their true selves could become quite confusing. Lo and behold the at times faint jangle in certain treble expression - especially with regard to piano and flute - had been tamed with no loss of resolution.