Allen,
I believe this
thread is about converting waste into a usable commodity. Certainly it would be great if the volatile gases can be utilized, but that is not always feasible. Making char(coal) cleanly (relatively) is the next best thing.
The rocket design is not the do all and end all in stove efficiency. A 3 stone fire can outperform a
rocket stove, and has in testing, depending on the variables. I am not poo-pooing rocket stoves, but I think it is a mistake to become married to the design.
Normally, if you are producing charcoal with a rocket stove, you are doing something wrong.
Gasifiers are very clean burning, more so than the rocket design, and they can be designed to produce char or burn everything to ash.
Theoretically, a rocket stove can be designed as a kind of gasifier (or perhaps more appropriately, a smoke burner).
To
answer your last question, Yes.