Toilets are admittedly a slightly unfourtunate and unpleasent side to the job I will admit. Really can't see why the passenger would want it back after it had been in the bog. Some people are strange.
Had an aircraft came in a few weeks ago. The crew reported a blocked sink in one of the toilets. Found that someone had removed the plug and the strainer (they just lift out on our aircraft) and then stuffed a load of carrots and a small plastic toy soldier down it.
It does kind of make you wander what drives some people.