The first one I made I stuffed a bit of paper into the monkey fist knot. I'll be replacing it with a marble like I used on my second one. It turned out better.
https://www.youtube.com/watch?v=31zkBObg-3g
Instead of a marble, I wonder if a stainless steel "pea" lighter from County Comm (government products) could be used for the core?
I've got one on my keychain now. With its O-ring, zippo fluid (napatha) does not evaporate over weeks or months.
AA