I've seen 3 people at my local club break them off inside the barrel. They are becoming somewhat well known for this. Two of the guys couldn't get them out, and had to call it a day. One guy and I struggled for the better part of an hour, and used up half a can of WD-40, pushing and soaking it before getting it out of his AR.
If you feel the need to go to a pull through system, the Otis models use a vinyl coated steel cable with threaded tips and brushes, which is far more sturdy and will not break. Most of the Hoppe's Bore Snakes, (including the three I saw break), were older, and obviously beyond their service life. What generally happens is the solvents attack the integrity of the Nylon cord these things are manufactured from. That's generally when they let go.
I don't see a need for them because I clean thoroughly after each range session. I think the whole "pull from the breech" sales angle used with these things is highly overrated. If you use a good, one piece, coated cleaning rod like a Dewey, and know what you are doing, cleaning from the muzzle is not detrimental to any firearm.
Personally, for cleaning a sixgun, I think they would be a total PITA. Trying to run that thing through all six chambers would involve a lot of fumbling around. With a short rod you would be finished with all six chambers in the time it would take you to pull it through one. To me running a brush and patches both ways dislodges far more crud than all of this "pull through only" nonsense they employ to sell these things. This is a case of a company coming up with a product that has some limited use, but has to offset proven methods which have been successfully employed for decades, in order to sell it. I put "barrel break in's" into much the same category.