We approved trenchless in my jurisdiction about three years ago and so far we have not had a problem. We require the installer the video the sewer before and after so we know they have no low spots. You should not need to have your house drain cleaned again. They dig a hole at the main and at the house. They send a cable through your existing pipe from the main. At the house they attach a metal head that burst the old pipe out of the way as it pulls in rolled plastic pipe in one piece. This is close to the same pipe we use on gas lines and it is very strong.