Reece,
First they could use a few mins of vigorous shaking in iso (I like to use a glass cider jug for this and leave plenty of open space for shaking).
Then, bake them at 250 for 5 min preheated (just long enough to inspect for any coatings coming off or melting, as glass should do neither).
These steps (inspection especially) can be a a small, but worthwhile effort (and only really needs to be done once).
Usually the smaller the better, just be aware of any possibility for them to be carried out of the mouth piece with splashing water and any possibility of them breaking (the vigorous shake in iso and inspection usually ensures no breakable ones).
I hope this helps.
And, Devo, I have never seen anything like that (may have been plastic beads sold as glass or something?) Cant go wrong with CLEAR GLASS seed beads though, right?.
PS: Reece, those beads in the vid seemed a bit effective, but IMO could have been stacked higher, could have had holes in the center, could have been much smaller, and probably could have been MUCH cheaper (as they look like they are some of the glass beads sold by pipe makers).
Please feel free to inquire with the other beadies in this thread if you have any further questions, and please let us know how they work for you.
Edit: I just saw your last post, reece, and guess I was a bit late with my response. Your glass shapes find sounds good and your steps to ensure safety sounds sufficient (at least). Irregular shapes can be nice because of how they can fit together like puzzle pieces creating a labrynth for the vapor to travel through. IMO the smaller the spaces between and the more of those spaces; the better
(water will climb beads that are stacked above the water level).