Besides the relative looseness of the above, the very narrow single point of contact makes is very easy to pivot the reed side to side. If your reed and table isn't perfectly flat, this won't seal it very well either. Also when you grab and push/twist the mouthpiece to tune, they're not likely to stay put. I would only use something like this in an emergency. But as many have proven before, anything that holds the reed firmly in place will work (shoelace, twist tie, etc.). I'm amazed that people will spends thousand on a horn, hundreds on a mouthpiece, $3-$30 a pop on reeds but draw the line at spending $6 on a ligature. Maybe it's just people's inner MacGyver that compels them to do stuff like this.