This is a very deep question.

Ethics and cleanliness are indeed two different concepts.

Moral mysophobia is a metaphor that compares morality to cleanliness.

This metaphor is very common, for example, curse words are called "dirty words", people who use bad words need to "brush their teeth", and ill-gotten gains are said to have a "brass smell".

A common saying in English is filthy rich.

Trash-talk on the court, etc.

Moral mysophobia, from this metaphorical point of view, naturally means that someone has too strong a sense of morality and is completely intolerant of immoral things.

It seems that the metaphor is not correct or wrong, it is just a conventional thing.

Everyone has thought so for many years.

In 1980, two scholars, Lakoff and Johnson, proposed in Metaphors We Live By that metaphors commonly used by humans are not without rules.

These commonly used metaphors are actually derived from human senses and real-life experience.

For example, why do we describe love as warm, but no one describes love as cold?

This is because when we hug, we feel warmth.

Why is the development of something in a good direction called "progress", while the development of something in a bad direction is called "regression"?

This is obviously a metaphor for walking.

Going forward will bring you closer to your destination, and going back will make you farther away.

Hope is often compared to dawn. For example, someone lights a lantern during the day to describe the darkness of society.

They explained that primitive people are instinctively afraid of the unsafe night, so the dawn of safety is hope.

This point of view strongly proves that human thinking and physical feelings are closely connected.

The old view that the mind and body were separate was wrong.

This has now become a classic theory in cognitive science.

Back to the topic of cleanliness, morality and cleanliness are indeed connected through people’s physical feelings.

Studies have proven that when people do something immoral, they are more likely to wash their hands.

There are many follow-up studies, and here is a relatively new and interesting one: What is interesting about this study is that if a person says something immoral, he will want to clean his mouth more, but he will not want to wash his hands.

But if you use your keyboard to write an unethical email, you'll want to wash your hands.

This confirms that there is also a relationship between moral sense and exercise style.