The double handed knife is an old Swedish way to make small kindling. The problem has always been that your knuckles most of the time get smashed. I took this problem to an inventor, Mr Billy Jacquet, who after some good thinking came up with the smart double handed SPÄNTAN but with the knuckle protection. SPÄNTAN is a dream since you can even use it singlehanded. It is successfully sold in various countries. SPÄNTAN is also manufactured in Sweden.
A humble suggestion from us is that Kindling should be made from soft wood like, spruce, pine which easily ignites and then add harder wood like birch but be also aware from using harder wood like oak, beech, ash etc which might damage your chimney since they burn at a higher temperature.