Hardening small parts in an iron wire basket with boric acid

[Joopie]

I've recently discovered Clickspring on Youtube (he makes clock and other clockwork stuff). He has a technique for hardening steel that looks like a nice alternative to using a forge. He makes a loose sleeve of soft iron wire into which he places the part. A little handle of wire sticks out for handling. Then he mixes up a paste of boric acid with denatured alcohol and packs this in and around the sleeve. This thing is then placed in the corner formed by three hard firebricks. Heat with a blowtorch to red heat and the boric acid melts, bubbles, and glows. Pick up the sleeve's handle with a needle-nose pliers and dunk in oil.

I haven't seen a post here talking about this. How many of you have tried it?

See below where he does it to heat treat a milling cutter:

 

[Stacy E. Apelt - Bladesmith]

The boric acid is an anti-oxide coating. What he is doing is a basic simple steel HT. Heat to red hot and quench. A couple firebricks as a backing is used by many folks who use a torch or HT.