I must not be in the right circles to know what "moop" means.
Aside from needing family friendly venues, I can't see trusting some of the people who go to Burning Man with large caliber air cannon.
As another aside, the ammo would be compressed chalk. I'm thinking that should be fairly environmentally friendly, and will allow calibration of frangible shells. Part of the design challenge is needing to design for a larger gun to get a larger gun, even though they're color coded for shot calling.