The "Boom" Comes from compressed powder. I found that powder alone would only "BOOM" if I doubled or tripled the charge I usually use with a PRB, unless I found a way to compress it with SOMETHING. 3X the normal powder charge uses MORE POWDER, and its weight(mass) to compress the powder, and that makes a very good "BOOM".
I could cut back on the amount of powder used by using a double charge, but putting a dampened cleaning patch down on top of it. The moistured from wiping the patch on my tongue adds Weight, and helps hold the cleaning patch after its tamped in place.
If I used paper, as in a Paper tube carrying a pre-measured charge to ease loading while marching in a parade, the paper came out as confetti, and caused NO fire hazard. I even used Orange paper once to make my paper tubes, stuffing the tube down the barrel After pouring in the powder. It added color to the confetti which many folks along the parade route liked. If I could have found red,white,and blue paper, I would have used that the next year to make the tubes!
My club has changed its rules for parade marches, so that NO ramrods can be taken along the route. They don't want us firing anything out of habit out of the guns, except powder and smoke( and flame). So, I now use more powder, and simply limit the number of times I fire the gun. I still go through a couple of pounds of powder along a typical parade route, shooting my .50 cal. rifle.
Oh, The Barrel is Really FILTHY when we finish( Surprise! :shocked2
I pour water down the barrel after plugging the TH, let it sit a bit, and then pour the gunk out. That tends to soften the crud sufficiently that I can then pour both Soap and Water down to begin my NORMAL cleaning routine.