The Kelly Kettle is basically a rocket stove, only instead of insulation that makes the flue gasses hotter and helps them burn more efficiently, it sucks the heat from the flue gasses reducing fuel efficiency. Though, that reduction in efficiency is made up by the way the Kelly Kettle heats the liquid. Removing the base, of the kettle, and placing it over your own rocket stove, which has properly insulated walls, will be the most efficient option.>cinder blocks to make a rocket stove
The walls need to be insulated for it to be a proper rocket stove, fyi. I guess tits can make up for that fact.