Not so Mr Ghost, the testing you refer to(which I haven't heard of) would be with a wrought iron barrel which has porous steel, filling the pores with some kind of lube would be possible and have benefits like a seasoned skillet in that type of metal.
On modern steel barrels that are non porous pitting would have no beneficial effects where as a mirror bore would have a bunch of positive things going for it. Pitting holds crud that a mirror bore wouldn't. Pitting holds fowling shot to shot making wiping between shots more necessary. With a mirror bore you may never have to wipe between shots because each loading takes the fowling out of the bore.
You don't have to have pitting to have a rough, hard to load barrel, most rifling bits chatter a bit during the process and leave rough lands and grooves. This is why people lap or refresh their bores to get rid of any roughness because it has so many detrimental effects on shooting. You can lap a barrel or put a couple hundred shots through it to "break it in" or smooth out the roughness.
I have a rifle I put up with Rem-Oil in the bore, I came back 6 months later and found a red potato patch growing in the bore. 6" groups at 50 yards became the norm, bummer.
I decided to get as much of the pitting out of the bore as I could, it was ruin or fix the bore which ever came first. I put Soft Scrub kitchen cleanser on a piece of green Scotch bright pad and started scrubbing the bore. After about 100 strokes I could see metal on my cleaning patch and was sure I had ruined the bore, a quick check with my endoscope showed that I had rounded off the sides of the lands and removed almost all of the pitting although their was a small bit left near the breech. I followed up the scrubbing procedure with a patch soaked with JB Bore Paste polishing agent and 100 more strokes with my ramrod.
This is what I ended up with, a mirror bore except for a little freckling near the breech.
Then it was off to the range at 50 yards, I was expecting disaster. I pulled my first shot to the left then got down on it, my rifle never grouped this well brand even with the barrel new from Rice and definitely not with a pitted bore.
I have since gone back with the JB bore paste and maliciously polished all my rifles bores as I have found a mirror bore is the best for shooting and the follow up cleaning.
I haunt the Muzzleloader Forum and the American longrifle site, everyone on these sites wants a polished bore, no one wants any pitting.