That certainly is a popular method, and can be very efficient & effective. But the folks I know who use drowning are those who live in areas where you cannot discharge a firearm, and they have neighbors who would report hearing the gunshot. They cannot risk that, and feel that stabbing or blunt trauma is not efficient or effective. Drowning isn't their first choice, but they try to make it more efficient by having the barrel pre-filled with the water. They are the ones who tell me that the raccoons struggle for only 30-60 seconds before going limp. They wish it would take even less time, but feel it's the best option available to them.