Hedgehog, I know you are in Ottawa so thought I'd let you know that in my experience the cleanest bathroom in the Rideau Centre is on third floor in Sears (the furnishings and appliances floor) as it is used far less than the others.
For anyone on this board who may be visiting Ottawa, the Rideau Centre is a centrally located shopping centre in downtown Ottawa, just a short walk from the Parliament buildings and on all major city bus routes.