Really Good Guess! And Very Close! But not exactly. Although I have actually been there with the garbage bag(s) and acetylene, and just the right mix of oxygen, many years ago. The resultant complaint call came from a small town five miles away. Five law enforcement agencies responded to the call. The FBI interview was intimidating, but since there was no malicious intent and no property or personal damage no charges were filed.
No, I consequently went to a smaller scale and a slightly more stable mixture. After that experience and after two oxy-acytyl garbage bags detonated in my hands due to static electricity I scaled down to party balloons filled with oxy-propane. And, I notify the neighbors beforehand so that I don't unnecessarily surprise anyone.
It is startling to the unsuspecting spectator, but surprisingly harmless, given good hearing and eye protection. There is a lot of Energy in sound and light, but because there is no Mass or Containment there are no projectiles and the energy dissipates within four feet. Louder, but Safer, really, than common aerial fireworks, which have less total energy but more mass and tighter containment.
Still have to be Very Careful about Static Electricity in the inflation process though! Ask me how I know. The beard having been carefully preserved in the last several years by maintaining a discreet distance during the inflation and detonation processes.