Cleaning the black water tank

Harbor Freight has a nice little camera set up that I bought for working on my Goldwing. It works well for inspecting the black tank without a charge for plumber. If you have access to hot water that you can put into the toilet, put about 10 gallons in with Dawn and Calgon and take a 10 minute ride and then finish filling it and the gray tanks. Elevate the off side of the camper and then drain the black tank and leave the black drain open. If you don't have a third gate valve, raise the hose higher than the tank and open the gray tank and it will flow quickly into the black tank and close the valves before the flow stops. Then drain the black tank again and again back flow with the gray tank. If you can do this while keeping the hose in the drain and keep the water moving, that is even better. Usually I stand on the hose to keep the end in the tank and pick the hose up close to the camper to create the flow into the black tank and just open and close the gray tank.