When anything comes up here about tools & notions I realise how many things I've bought and not used or upgraded them to another gadget I liked better. I blush at the money I've spent on all those items, even if they were all just a few quid at a time.
I don't even thread much elastic through casings as I prefer the sew on and fold under method for skirt elastics.
I've got the plastic ones but often 'forget' to use them, being too lazy to look for them when I need them (the large one doesn't fit in my little sewing tin) and end up using a safety pin! I think it's partly because the last I time I did use them I found the elastic rather unwilling to go through the slot. I have the long plastic type in the video and haven't ever used that because I forget I have it (what use am I?!!!) so if I do come across the pincher type I bet I'll succumb telling myself it will take different widths to push through (all those casings I rarely sew) and will be unable to resist the overwhelming argument that it'll fit easily into my little sewing tin so I should be able to find it because I'll see it every time I go in there. Sigh.
Btw, I have a double ended version of the ballpoint one (eyes each end, no ballpoint) and I use that regularly for weaving overlocked chains back through the seam. I keep that in my little wooden overlocker/chainstitch tool box so never lose it. I think it may have been recommended by someone here and, being significantly longer, I find it an improvement on the large tapestry needle I used previously. No embarrassment there at least.