This seems to be true.
I used to work in a paint factory that had one set of bogs in the main building and was staffed round the clock, 7 days a week with 40-50 potential bog-users on each shift - and yet in the four years I worked there I never encountered anything half as grim as the stuff you hear about in office bogs.

Though it might have helped that those bogs were cleaned every day rather than just once a week.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Sat 4 Feb 2012, 3:19, Reply)