twins, I think I see how that might happen, depending upon how the particular cable is built. In this case, the little nylon disk is more like a "plug" that's tapered toward the bottom, so binding seems like less of a possibility. Might have to cut one cable, though, because the housing seems pressed or otherwise attached to the base of the metal tube. I'll examine it more closely.
joe-wiseguy has indicated that this works. If it does not, I'll try your other suggestion, though my local bike shops never fail to disappoint me, even when I am looking for something as simple as a cable.