I recently took a foray into arm knitting - my brother's girlfriend wanted an arm knitted blanket for their new apartment but was struggling to find one that was affordable and in the right color. She asked if I could make her one, so I took a look into it. The biggest struggle with this project turned out to be the yarn. The yarn needs to be custom and rather large/heavy weight. Not even chunky yarn will produce the same effect.
I bought yarn from Amazon - it still ended up being rather pricey, but I think that is really just the nature of the projects. Using my arms as knitting needles turned out to be incredibly awkward at first. I actually redid this blanket 4 times before getting it right on the fifth go. Thankfully, this really doesn't take long. I believe it probably took me 20 minutes for each go round - which is great because you are really hindered from doing much of anything when the yarn is just hanging around your arms. In order to give some idea of scale, I wanted to share the picture below where I have it laid out on the bed - this blanket is meant to be a cozy throw for the couch so it is a bit smaller, but ultimately will provide a lot of warmth.
It was actually quite a cool project and my brother's girlfriend LOVES how it turned out. I really do love the look of these blankets. The custom extra large yarn is ESSENTIAL for this look to be replicated. You may see a few tutorials that claim you can join three to for skeins of yarn together for the same look - but I was unable to do so, so I am very skeptical of the claim. Go with the larger custom yarn; even though it is pricier it will make the project easier and will give the look that you're going for.
Have a great Wednesday!