I used a single treatment of an enzyme-based cleaner on my kitchen drain. It didn't seem to help or hurt. I read that sometimes using a plunger after the treatment can help. When I used the plunger, sandy black sludge started coming up. I continued plunging while running hot water, but couldn't clear the blockage. I emptied the sink by scooping out the water. I poured in baking soda, vinegar, and hot water. I took off the p-trap and pushed an auger about 10 feet into the wall before hitting an obstruction--cannot tell if it's a T or a blockage. Didn't want to push too hard as the pipes are old. I put the p-trap back on and went back to plunging while running hot water. Must have scooped out more than 20 gallons of sludge by now. I keep thinking I must be close to clearing the clog, but more sludge just keeps coming up. Anybody have any suggestions or ideas? Any help at all would be greatly appreciated!