The history of cleanliness in humans is incredibly complex. What you have to remember is that the very recent ideal of clean is based around knowing that microscopic organisms cause ill-health. We don't just clean to have it look or even smell clean, but to a level that we can't even sense. This is, for obvious reasons, a 20th century way of staying clean.

Cleaning specific to body odor goes in and out of European culture over the centuries as things like the Turkish baths are adapted in. Those bath houses that the Romans loved so much were too scandalous for the early Christians. That phrase "Cleanliness is next to Godliness" is late 18th century. In the early years of Christianity not only was the process of bathing found decadent and sexualized, but overly focused on the physical self instead of the spiritual self. There were religious figures that encouraged people to never wash for these reasons. And body odor itself wasn't always seen as "bad". Obviously, it can be unpleasant, but the smell was considered something more personal and intimate. There's a reason girls still steal their boyfriends sweatshirts today.

I could go on and on (and really need to do a Podcast or something on this), but specific to body odor a lot of changes occur in the 18th century. Having left behind the "no washing" encouragement centuries before, people had turned to using clean linen undergarments to keep their bodies fresh and focus on washing the hands and face. Many manuals discuss how often to change and how to clean these garments in order to keep from being offensive to others (it really does work). And that is how cleanliness throughout the 19th century is discussed as well- avoiding being offensive to others. Be it through the invention of olive oil based soaps gentle enough for the skin in the late 18th century, the advancements in running water or heating water, or understanding of sanitization, one must always look and smell clean to be a respectable member of society. The 20th century instead pushes us to be clean for our health as much as it does push us to be fearful of that terrible odor we don't know we have. A huge change occurs between the two World Wars that means most people now have access to running water and baths or showers in their own homes. Hard to believe that municipal (public) showers were still being built into the 1930s to service those that didn't have access to it any other way. Coupled with aggressive ad campaigns for products and a revolution in how we clean ourselves occurs.

The Dirt on Clean: An Unsanitized History is a good overview of the topic, though I can't say I agree with all of her conclusions on alternate cleaning methods.