I've heard this called other things, but I call it a char tube. It's an effective way of having charred material on you all the time and takes a spark very easily. It's also a very cheap if not cost free project that will probably out last you and I.
All you need is some tubing...I used a small piece of brass and 100% cotton cord. I found some old clothesline and removed the nylon core. Simply cut to the length you want and tie a not in one end, push the knot free end through the tube until it sticks out and char with a lighter. From that point on it will remain charred from using it. To use just push out the knot free end and hit with a spark, use it as needed and pull back in to put out holding a finger over the end.