'Two Flies only' per toilet

This is something that I can definitely get on board with.  Two flies or less per toilet - that's a goal worth aiming for.

Beijing sets 'two flies only' public toilet guidelines (May 23, 2012, BBC News) Authorities in the Chinese capital have set new standards for public toilets, including a stipulation that they should contain no more than two flies. The new rules, published by the commission of city administration, also set standards on odour and cleaning litter bins. Toilets in places such as tourist spots must comply with the new standards. But it is not clear whether failing washrooms will be punished and if so, how. The new rules also cover cleaning, the use of equipment and training for attendants.