I'd like a link to this, not just the pic. What frequency? What, if any, substrate?

It's straight DC and it counts on coil kickback...basically, "don't try this at home".

https://www.capturedlightning.com/frames/shrinker.html

Oh, now I totally love that page because further down it quotes a Mark Twain quip that's applicable to all mentions of capitalism, socialism, communism, etc. That one's definitely a keeper.

^^ The quintessential loophole.