These devices make for the BEST "Super Soaker" on the block.
Fill the "fuel" tanks with water instead of the usual flammable material, add the recommended pressurising gas, or even basic compressed air, and liven up those summer kids parties, big time.
Good (and cheap) "training technique" and will atract a LOT less "attention" than going "live".
I remember seeing a demonstration of just such a technique at an "open day" at the old "Officer Cadet Training Unit" at Wacol in SE Qld, way back in the mid 1970s; there may even be a photo in an old album somewhere here.