We had problems with a completely clogged kitchen sink that no chemical cleaner could fix and leaking pipe in the ensuite bathroom sink.
Dayvid from New Canadian came by and showed us how badly our drain pipes were clogged with hardened grease and guck that had built up over the years. He told us not to use Draino or other chemical drain cleaners because the acids tend to erode away the sealant material in the pipes, and that was what was causing the leak in the ensuite bathroom sink.
He completed a very thorough power wash of all of our drains and recommended an enzyme-based drain cleaner instead of the harsh chemicals. Bio-Clean.
He also recommended fixing the angle of the dual sink drain so that the sinks drain better and put in all new piping.
I am very happy with the results and the explanation of the problem with camera images to clearly show how bad it was, and recommendation for long-term maintenance.