I used plain cotton balls but petroleum jelly treated ones could be used as well. The amount of cotton needed is small, just a few winds. The first wind or two of cotton being moderately tight with the final wind left loose and fluffed so it can catch a spark more easily. The “match” can be left to burn completely or blown out and reused. During my experimentation with a Fatwood stick about three inches long I was able to get an average of six “lights” from a single cotton ball before it became too short to hold comfortably. I’m calling them Fatwood matches but in reality any twig or sliver of wood can be used, even spent matchsticks can be relit.
The neatest discovery is the method I’ve found to light them. The cotton wrapped stick is held with the striker when scraped against the Firesteel and you end up a holding a lit “match”. The technique is pretty sure fire as the cotton is in close proximity to the sparks for the entire length of the scrape. I’m only using the first inch or less of my Firesteel to light these “matches”. The concentration of sparks is especially advantageous when using a smaller Firesteel such as the BSA HotSpark.
The Fatwood match makes a nice mini-firestarter for my home-built GSI bottle cup stove (that’s a teaser and possible subject of a future DIY article). The longer burn time compared to a standard match makes lighting the sometimes-obstinate Esbit tablets easier. I’ve also discovered that I can use this method to light a classic fire starter…the Magic Birthday Candle. The cotton should be wound with the wick exposed so that it can catch fire without getting smothered as the wax melts into the burning cotton.