There was a really nice one in the D&D Motel set by Davo and Dendras, but the model doesn't seem to be available at Renderosity anymore. You would have had to buy the entire motel to get the toilet which was about $50. All the models including the motel are great and very realistic, but memory hoggers.

Poser 2, 3, 4, 5, 6, 7, 8, 9, 10, Pro 2014, 11, 11 Pro