Hawaii was clearly the center of pyrotechnical school pranks, since fire works were not outlawed due to the chinese attachment to them during religious ceremonies. Radford High was the high school most of the Pearl Harbor (Navy & Marine Corps) and Hickham (Air Force) kids attended. And we worked hard to make our parents proud.
Take three rolls of TP into a three-holer boy's john, sharing a wall with the girls on the other side. Stuff the TP into two of the toilets, allowing the paper to swell up and seal the drain. Light up an M-80 or cherry bomb and flush down the third john (they stay lit underwater) and kick the last roll of TP into place. Result: since the boys and girls johns shared the drain, the explosion would blow the girls off the seats, usually with some product of their efforts slammed into their bottoms. One on occasion one of my friends, now a Navy Captain, just flushed the commode with every seat on both sides occupied, during a football game. Unbelievable! One old guy just in a stall next to the explosion thought we had been nuked, and was screaming for a geiger count on his butt. The second is far more evil, but was well established at our school. Take a good sized sewing needle (like you'd use for sewing carpet) and thread with approximately 18 inches of thread, tied off at the end. Hold the thread at the knot, between thumb and forefinger and hold your hand upright from the elbow, palm facing your target. Allow the needle to dangle near the back side of your elbow. By snapping your hand forward in a rapid movement, the needle will flip over your hand and fly point first at incredible speed (enough to stick it in a concrete wall 20 feet away). The thread acts as fletching, trailing behind the needle as it flys through the air. Jocks were especial targets, with extra points for burying the needle up to the thread.
The last involves a shotgun shell with the pellets removed, and a mouse trap. You get the idea. A military high school was no place for the weak.