https://www.homebuildingandrepairs.co... Click on this link for more plumbing, repair and remodeling videos. Here's another plumbing trick you might not be aware of and after the video, will understand why some plumbers install clean-outs in certain areas instead of in others. I've been trying to point this out to other professionals who really don't care, because they usually won't be doing the repair work, but you might, if it's your house.