How long does that take to get a fine grind? Not going to lie that seems odd considering the other options out there,l do you find that its creates a size that no grinder can match? That's a techinique I never would have thought of.
For $0.25, hard to beat.
Not long at all. I usually shake it for about 30 seconds, then check to see if it's fine enough yet. The number of repetitions depends on the starting state of the material. If you start with whole buds, you can get any grade of grind you like using this method.
The only fine grinder I'm aware of is the Magic-Flight finishing grinder, which I've never tried. Lots of people use coffee grinders of course, but again I've never tried one. Unlike the MFFG, that's an alternative I would never use.
A friend of mine says that I'm knocking off the trichomes, and there's truth in that. There's a fine layer of trichomes left inside the bottle, but you can harvest it if you like. Any grinding method knocks off some trichomes, it's just a matter of degree. I'm pretty sure the coffee grinder is the worst offender on this score. I've never been able to detect any difference in the quality and quantity of vapour from a fine grind produced this way versus grinding upside down or any other method, but perhaps someone else could.