all that smoke was not modern day propellant, for sure.im positive it was black powder.
Are fireworks common there? Easy enough to to empty some firecrackers
Yes. Black powder.
Very low tech. Charcoal, salt peter and sulfur.
Not clean, not pretty, but functional.
I suspect the electrical firing would have required electrical igniter surrounded by something quick burning. Flammable liquid or match heads. When my kids were small, we shot model rockets. When we did not have factory igniters, I would make one by wrapping very small copper wire around a match head. Stuffed that in the rocket motor and put the juice to it. Worked as well as factory igniters.