I think ol Ross ate some good ol bacon & eggs from grandma's iron skillet that morning & a bright idea for an article hit him. The scotchbrite pads are to smooth out the tiny burs & etc. left over from the rifling machine & is a barrel makers tip that has been done for years. Ask Don or John Getz what they do with theeir barrels. (Getz Barrel Co.) They have been making top quality barrels for years & years.
If today was in the 1700's it would be a great idea to season a barrel, as stuck out in the middle of nowhere with a Cast or Wrought Iron barrel , ya had to do Something to keep it from rusting. But todays modern steel is not porus like the old barrels were & not a cast iron skillet. With todays rust inhibitors, IMHO it is a TOTAl waste of time & poor use of an oven, altho now that I think on it, the bore butter would most likely be pretty good on some homemade biscuits, which is the only thing I can think I would possibly use it for.
1: Clean that bore good & I mean whistle clean. Take a breech scraper & scrape the face of the breech, use a breech brush & get all the fouling out of the breech area.
2: Swab that sucker dry. I even wad up 2 patches & cram then down the barrel into the breech in Front of the jag & force them tight in there & wait a few min to be sure they soaked up all the moisture, then take a worm & pull them out after a few min. This will absorb the moisture you didn't reach in the edges of the breech.
3: Use any good rust inhibitor, mineral oil, motor oil, Break Free, Ballistol, etc. to preserve the Bore til next outing. Make sure hou get enout of it to squirt out the vent & if percussion, remove the nipple & clean out under it. I take my clean-out screws out too if so equipped & clean behind them.
Some say all natural stuff & no petroleum.. I don't think it matters at all & have tried both lots of times, can see absolutely no dif.
I say C L E A N and No Moisture is the most important part. Then put whatever ya want on it as just about anything will keep it from rusting if you have bare clean metal first. You are gonna swab it out before ya go shooting anyway, so it makes no dif if it is oil, grease, petrol products or natural produces.
Go to ANY national ML shooting evento & see what they shoot. You will find 99% of them shooting Clean bores.