Interesting, I've never seen those on any of the Wicos I've worked on. Is that an actual Wico-manufactured stick? I don't recognize it, though I haven't seen Mad Planets or Mach 3 sticks in person.
However, I have seen many Wicos with zip ties used the same way, to tighten up the normally somewhat sloppy plastic leaf holders. They go right around the leaf, the same way. Snip off the excess, and you're good to go.