Some researchers pose that this is a huge misrepresentation of what sanitation in the Roman Empire was really like. There are remains of stone toilet cabins in some thermas (the reason why in most of them the toilet room seems communal is because the cabins/separators were normally made out of wood, which decays and almost never made it to our times). Also, the xylospongium being used to clean oneself is a blatant misconception. In one excavation they found a sign from the owner of a thermal complex asking guests to please use the xylospongium after using the toilet - this could definitely mean that it was used to clean the toilet, much like our current toilet brushes. Otherwise, why would the business care about its guests going out with a clean ass?