Clean & Decent: The Fascinating History of the Bathroom and the Water-closet, and of sundry Habits, Fashions, and Accessories of the Toilet began as the backstory for an exhibit at a building convention. It became a delightfully well-informed history of western toilet habits as told from Ancient Egypt to the early 20th century.
It is not a history of hygiene in general - of health and medical care, sewage systems at large or the public welfare. Instead it is a very personal look at those most personal of household spaces: the loo.
Entirely fascinating and regularly humorous, you will be well rewarded for your time.