The most important aspect of SAFELY cleaning any barrel with rifling is to keep the cleaning patch and jag or brush centered in the bore. So that nothing BUT the patch or brush touches the rifling. That means the rod , rope, string, or whatever is pushing/pulling those cleaners does not touch the bore.
There's two areas of a barrel that are critical to accuracy. The crown and the throat. The crown is THE most critical. Wear on one side of the crown will quickly show up on the target.
Now you can't tell me that in pulling that rope while holding onto the rifle, you are keeping it centered in the muzzle. Or that the rope isn't dragging on the throat before the brush/patch enters the bore.
Okay, I'll admit that the nylon rope probably won't wear much on barrel steel. What I'm concerned about is the fine dirt that gets embedded in the weave of the rope being dragged over the extreme edge of the crown. Keeping that rope clean is nearly impossible. Even if it were totally clean, there can be abrasives in the barrel after a hunt. Ever see what wind does to a plowed field? Soil is nothing but tiny chunks of rock.
As far as copper fouling causing rust, well prove it to me. Nothing we shoot these days is corrosive. Unless we go out of our way to load black powder in a modern firearm. Yes, a barrel left uncleaned, then exposed to high humidity can rust if not oiled. BUT taking a bore snake or Otis kit with you to a range, so that you can clean BEFORE heading home makes no sense. Unless, of course, you don't intend to clean as soon as you get home. The a quick pass with an oiled patch would make sense.
The more people I meet, the more I love my dog
They're going to get their butts kicked over there this election. How come people can't spell and use words correctly?