Cryo treatment of metals has been going on for a very long ttime, I was involved with a project 10 years ago that used it and it seemed to be a well established contractor doing the work.

By the Buy, VERY energy intensive.

Cryo is also big in the audiophile aftermarket. Cables, mostly, but I've heard of cryoed vacuum tubes. Check out www.cryo-parts for the prices. I've been thinking about their silver wire, which isn't unreasonable compared to a lot of copper speaker cable you see these days.