Very unfortunate how people will mess with hot water and steam when they have no clue what they are doing. On the other hand, unscrewing a 6" cleanout filled with two stories worth of sewage, well, that kinda serves the idiot right. I noticed on my septic system there's a cleanout heading out of the house to the tank in the basement. I always thought that was a stupid place for a cleanout because if the septic system is clogged, when you unscrew the cap you will get all the sewage in the house, plus anything at the top of the septic tank coming in the basement. I always thought a septic cleanout was a raised pipe outside of the house in the line to the septic tank.