I'll tell you from personal experience that even a well-clothed forearm is not a good way to break this stuff off... I've got permanent line-burns in my SST jacket from doing this. I now wrap the line 4-5 times around the fish-bonker in my boat.

Another method of breaking off braid that I was told about is to wrap it around the frame of your round-style baitcasting reel... let the frame take the abuse instead of the gears. Haven't actually tried this yet, but I would reserve it for reels with a strong one-piece frame. Don't know if the wimpy crossbars on some reels could handle the stress.