1. Open the sewer 2, and plug the dredger in. 3. When it can&;t be plugged, hold the head here with one hand and turn the handle 4 with the other hand, and it can be pulled out almost at the same time. There are definitely many things blocking the sewer. Clean it up and repeat 5. After that, flush the sewer 6 with water, and clean the dredger for next use. 1. Open the sewer 2, and plug the dredger in. 3. When it can&;t be plugged, Turn the crank handle 4 with your other hand, and you can pull it out almost at the same time. There are definitely many things blocking the sewer. Clean it up and repeat 5. After that, flush the sewer 6 with water and clean the dredge for next use.