I just got this one from my home inspector. This is the cure all from what I hear. It is called Hair and Greese. Go down to your local Ace or hardware store. No more plumbers, very legal potent stuff but it is the trick.
Just thought I would let you know. You have the naging toilet or shower that you have to clean out or plunge every few months, here you go.
Stefan in the Napa Valley.