I guess I'm one of the jokers - sometimes breaking a rod with inattention while loading - mostly talking to someone else and not watching. I usually watch what I doing, though.
I see a potential problem with those noodle rods that more and more people show up with, the ones sold as being unbreakable - they touch the bore several times, scrubbing away as they seat a ball - even well down from the muzzle. Same thing happens with too tight a patch or use of a brush with a .17 cal Dewey rod in the little bores, which is way to whippy for constant use.
Fellow over on Nitroexpress was showing his fiberglass rod - yeeeowch!. He uses a bore guide made from a bolt - complete with some of the threads still on it. I'd not even think of doing this to a barrel.
The 14 bore has well over 4,000 rounds through it, still shooting sub 1 1/2" groups at 100 yards. Anyone who says a muzzleloader wears out a barrel in 2,000 rounds is just talking to hear himself - now, if said person was shooting slugs with heavy charges, pressure helps with wear, however even antique ctg. guns are still shooting slugs into sub 2' groups at 100 meters - go figure.
Round ball shoots as much as anyone and he's still shooting the same barrels.
Using a bare fiberglass rod for loading or cleaning, is like using a long fine tooth round metal file for loading ancd cleaning. I used a fiberglass rod for a while with a .50 slug gun I had, only to have to re-crown every 200 shots. Every 3 or 4 times to the range, I'd have to cut off 1/8" to 1/4" and re-crown. The wear wsas very visible. I'd re-crown when the groups opened to 1 3/4" from 1" at 100 yards. It was a very accurate barrel and I shoot irons back then, somewhat better than today. Hey - I could see!