Very neat! Easy to remember and tie. I just tied your guitar bead stopper in thin braided nylon string, and it formed a rock hard knot that I couldn't untie, so it should probably be used only for permanent attachments just like what you are doing, tying beads to guitar strings. It turned out to be self-dressing, too, so it's quicker and easier to tie than Ashley's stopper. Congratulations on finding this neat solution! I hope it doesn't weaken the string too much. It has many turns so maybe it shouldn't, but it still would be nice to see it tested and compared to Ashley's stopper.