Take the RV to a certified dump station and pump out all waste and water from the black water tank. Bring the RV back home, park it and set the parking brake. Turn off the RV's water source. Put on protective equipment and open the black water tank panel at the rear of the RV.
Unscrew the current hose clamps on the black water tank valve. Go in the RV to the bathroom and unscrew the hose clamp leading from the hose on the back of the toilet. Pull the hose off the toilet and off the black water tank.
Slide the hose snake tool into the black water tank hose and push/pull through the hose several times. Be prepared for waste pieces to come out of the hose as you snake it.
Slide two new hose clamps over the hose and push one end of the hose on the back of the toilet and the other to the valve on the black water tank. Slide the hose clamps over the toilet fixture and the black water tank valve, and tighten them into position.
Apply a ring of silicone caulking around the attachment points of the hose to the toilet and tank.
