I don't want to get a thread drift going, but that reminds me of one of our captains who strapped a pair of MAC-10's on his Quicksilver ultralight and strafed the desert!! We used to hunt coyotes out of J-3's and Super Cubs. Several great prop strike stories....
But back to tow planes-- the AgWagon and Pawnees I used to spray and dust (yes, real sulpher dust) with had the dump gate lever on the left side of the cockpit mounted on the floor with a mechanism under the floor leading to the gate itself. As I recall, there was an adjustable stop to regulate the flow of dust from the hopper through the spreader (and into the cockpit--at least I never had fleas). When they convert a Pawnee to a towplane the hopper is usually removed along with all the hardware. Maybe everyone should think twice about taking that lever out. It can provide a lot of leverage on the tow hook.