Okay! I found a nice video about making a rocket stove out of a concrete/perlite mix. He made a few errors in his design, but he shows the comments about correcting these, so it is ok.
https://m.youtube.com/watch?v=...
His way of making everything look easy is important to me because I took a course in the Montessori teaching method. I am obsessed with the part of the method where you practice until you can make what you are doing look easy so that students will do it easily also.
It is important that people know that making a rocket stove can be easy.
Rocket stoves have their vortex in different places according to how they are designed. This guy is mixing ideas from more advanced rocket stoves with his simple one. The vortex for the simple ones tends to be in about the spot where the elbow inside is located.
The vortex whirls around and collects the gases and carbon particles given off by the fuel. It burns the gases and carbon as well as the fuel itself. This is what makes rocket stoves so efficient. They can save up to 95% of fuel.
That kind of efficiency is not going to happen in one of these simple homemade rocket stoves. They will still save you a whole lot of fuel. At the same time they burn very clean and can help stop making climate change worse.
