Idea for Audio and Power Cables

There was a guy over here some years ago was using mercury in tubes for speaker cables. Very dangerous stuff, Yikes!

Here's another idea for containing stray electrons (Tara Labs sells a cable that suspends the conductors in a vacuum and charges $15,000 for speaker cable).

https://www.youtube.com/watch?v=u19QfJWI1oQ

If Sulfur Hexafluoride can neutralize a stun gun, it should certainly contain a few measly audio electrons.
So why hasn't a "future enterpriser" tried this yet?

A recent development in power transmission are superconducting cables that operate at a couple hundred degrees below zero, cooled by liquid nitrogen. The main feature is zero resistance to the flow of electricity. Hmm, wonder what those cables would cost?