Cat,
That's correct. I do a double wrap of heavy duty foil around a 1" dowel, flatten one end, pour the measured powder in and twist it off.
To shoot it, it's like any other cannon. I just slide the charge in and seat it with a little rammer. Prick the foil, insert a short piece of fuze, light it with slow match on a linstock and BOOM. Really spectacular at night. LOTS of fire out the muzzle