That slightly bent barrell for a WW2 German machine gun so one could shoot around a corner, invented by a General who was smart enough or crazy enough to spend the entire war in a mental institution.
As a prop would pop around a corner and back a patron might get whacked by it. Maybe a shadow-maker sending just a mere shadow around the corner would be a much better product?
"I just got smacked in the face!"
"Who did this?"
"The Shadow Nose!"
IF it were a mere shadow they could fit into any size hallway.