I have three of them myself because my mom's friend sells them. She also gave me the materials to make one, but I found it confusing to do. But the inevitable has happened as a knitter: someone requested one of me and I needed to actually figure out how to make one. Which I found to be a bit tricky. (This video is the one that finally clarified it for me.)
My mom's friend calls making these scarves easy. I...didn't really find it so. I normally don't like super lacy or complicated knitting--I prefer it to be at least mostly mindless. This is not mindless. Oh no. You are constantly having to look for what hole in the scarf you're supposed to knit into next. But even worse than that, this kind of yarn TWISTS ITSELF THE HELL UP so that you are wrestling the shit out of the yarn every 3 stitches just trying to untwist it enough to knit it. For a 30-ish yard scarf that is only 6 stitches across, it felt like it took forever.
This is how I finally ended up untangling it: after finally untwisting it, I flattened it out, wrapped it around itself, and then had to rubber band the end I was working on so it wouldn't come out.
I finally finished it today: