How to Build a Swedish Fire Torch Video
A Swedish Fire Torch burns the wood from the inside out. It lasts a long time and is a great cooking stove.
This video was made for the Waldhandwerk Challenge. It looks to me to be a type of Bushcraft Skill. But it could as easily be a Off the Gridder skill, bug out skill, or survival skill.
Have you tried to build one of these? Is it as efficient as it looks?