This shampoo gave me the topic for this week. Now, people rarely think about it but baths were not always like they are today. The dirt from Morocco was not uncommon for scrubbing away other dirt. This does not mean the dirt in your backyard but dirt found in creek or river beds. It's coarse and easy to wash out with water.
Before the age of bath tubes, people washed in rivers and streams were the water was clean. Dirt, like I said already, was used in place of soap.
In the Roman Empire, public baths were built. These were whole buildings with 'baths' the size of swimming pools. In fact, swimming was part of it. Depending on the city, baths would be for everyone or they would be separated into men's and women's. People would go down into the pool, swim around, come out and lather themselves in oil (or ask someone else to do it- kind of like sunscreen at the beach), and then jump back into the water for another swim.
Water for these baths were brought in with aqueducts, something lost during the Dark Ages and only rediscovered in the Modern Age. Either Hot Springs or slaves working furnaces provided the hot water for the baths. This site has a couple of descriptions from people at the time.
While the Roman's bathed often, Europeans during the Middle Ages bathed once a year. It was commonly believed that if someone bathed more than that they would wash off all their skin. Imagine the stench. No wonder perfumers made fortunes so easily those days.
Once a year baths were also preformed in the time of Queen Elizabeth I. Writings of the time tell of how suitors would come to visit the palace. One such suitor, a prince, supposedly bathed often and it repulsed the Queen's courtiers.
For an American story, President William Taft had a new bathtub made specially for him in the White House during his presidency. This was necessary as he was the fattest president in history at around 332lbs. It is often told that he had the new tub made after he got stuck in the existing one.