I just recently bought one in 32-40 and have been trying to clean a sewer pipe full of crud out of it. I'm thinking I can get it done but will of course require lots of time and elbow grease. I've been using Kroil and CLP foaming bore cleaning. Its doing the job. After a regime of cleaning I ran a bore scope down the tube and there are changes taking place each time. What they are at this point I have no idea but I'm going to get it clean come hell or highwater. Anyone have similar experiences or products that were MIRACLES!!! Thanks