Animemes

People have been cleaning themselves for essentially forever. Bathing was not as common as it is today, but we know people have been washing their hands, feet and face regularly for many thousands of years.
Cleanliness features very heavily in religion dating back thousands of years, and the earliest soap recipe is from ~2500BC, although we know they were making at scale hundreds of years before then.
Wells to make water available in places where there's no stream or river date back even further to the ~8000s BC.

Most people weren't rocking perfumed soaps and immersion in hot water, but washing your clothes with a homemade soap, scrubbing your feet, hands and face with cold water and a rag every day or so and likewise your body roughly weekly was available to most people at a minimum. If you were near a river or body of water, like humans tend to prefer to live, washing your feet, hands and face every morning and a weekly scrub was perfectly comfortable.

Primates are generally very conscious of grooming. Humans are unique in regularly washing with water, but we're also unique in being nearly hairless, remarkably greasy, and clever. It tracks that we'd figure out the water thing pretty fast.