That's not how to do it!
First one must pick up a case and hold it over the press while grabbing a bullet. This ensures enough time for the powder to be evacuated from the case and dispersed gently, over as much accoutrement as possible. When one finally notices there is leaking powder everywhere they must be sure to
not know where to put the leaky case, and wave the pouring powder in a Witch Doctor fashion, blessing every nook and cranny with the power of fire.
When cleaning up, after one has regained composure from the ritualistic chanting, use a light solvent (like brake cleaner) to attract the kernels to the cleaning rag. Then marvel as the solvent dissolves (TA DAA!) the gun powder into a smeary, flammable, gooey mess.
Experience is the best teacher, not the least cruel, but very effective.