However DO NOT ALLOW TO GO DOWN YOUR DRAIN! It is,after all,a clay,what sort of mud is clay? pretty much waterproof that's what.'Lines your drains a treat.I've just spent a miserable sunday morning poggling it free...proper misery.
Wash it off into a bowl and think of a sensible,organic binning method,don't run it down the sink...end of!
Another wonderful thing...hindsight!