I don't know what Youtubes you found, but in a quick search I hit one by Larry Potterfield, scanned through it and saw how boiling turns the red rust to black and produces a black velvet which he takes off with steel wool and a fine wire wheel. That's been standard practice for over a century. Isn't that what you're talking about?

Stupidity has its way, while its cousin, evil, runs rampant.