That's what breaking-in is all about. This is a lot of cleaning, and it explains why you've seen some shooters at your gun club endlessly pumping cleaning rods. Unless you use the right technique and equipment, irreparable damage can be done to your new barrel, which is a distinct possibility when you take into account that most local shooting-goods outlets seem to have a chronic aversion to supplying their customers with decent cleaning rods, brushes and other cleaning supplies. All told, only a half-dozen or so makes of rods out of today's many are fit to go in a rifle barrel. So to begin with, unless you have a good rod, or are willing to buy one, you'd best forget barrel break-in.
Jointed rods are a no-no, as are rods with crooks, bends, rough surfaces or nonrotating handles.
There is some debate on the merits of rods with a soft coating versus uncoated rods, but it doesn't matter as long as your rod is straight and clean and has a ball-bearing handle so that the patches and brush easily follow the rifling. As for patch jags, I've given up trying to find a really good one-I make my own or modify the existing halfway decent ones. Most custom-barrel makers strongly recommend against them because they can scratch the bore, making it even more susceptible to fouling. Another essential item is a properly fitted cleaning-rod guide. They also keep solvents and other gunk out of the action and trigger mechanism, so always use a rod guide when barrel cleaning as well as breaking-in.