Rice hull BP is an easy way to make BP. It sure does beat all the effort needed to granulate.
I have made it myself, but never used it in a cannon. That is still on my "to-do" list.
I would be afraid to use it behind a ball because it is not all that uniform of a product. I have been tempted to try it in very reduced load blanks to see what happens, but I do have some reservations about trying it.
I am not really sure how "powerful" it is. It might be more powerful than one would initially think by looking at it. The apparently large grain size is deceiving, as all the powder is on the surface and it burns very quickly. It certainly has lots of exposed surface area, and as jeeper says, it's classic use is in pyro burst charges, but not lift charges.
In burst charges you want an absolutely maximum, short duration, very high pressure boom. Unlike a barrel, where there is time for the pressure to build up and be used, in a shell the pressure build up is all over the instant that the shell ruptures.