Tree roots clog main sewer line?
You have to replace with ABS pipe lillie. Otherwise they will grow back into the teracota even if you get them out. If they have grown into the teracota then you have holes or gaps in your mains somewhere. The hole thing is not good. Seriously consider whether you want to spend a lot of money on getting the roots drilled out – if that is even possible – or save to replace with ABS pipe. The roots won’t get through ABS.