I have a drain line from my washer to the sewer line leaving the house that is getting slow. I took apart a plastic coupling today to see if there was anything in it. It was almost full of this black soft material that crumbles to the touch but sure plugs up the drain. Is there any chemical that I could put in there to remove it? I tried three gallons of bleach and it didn't seem to help. The line is 2" Genova PVC.
Thanks