Bathing in Mongol beliefs
One of the strange beliefs of the Mongols is that bathing will make you prey for dragons, so they never bathed or washed their clothes!
It was known that the Mongol tribes had strange customs, some of which were acceptable, some of which were bad, and some of which aroused disgust. One of these customs was their complete lack of hygiene, as everyone in the Mongol Empire did not bathe.
The reason for this custom is due to an old myth that says that dragons controlled the bathrooms, and if someone bathed in them, this would make them dirty, and thus the dragons controlling them would become angry.
The lack of cleanliness also applied to the clothes of the Mongols. They would never wash them, no matter how long it took, and would not change them until they became rags, except on very special occasions, such as holidays that required a special dress.
Their unpleasant odors did not bother them at all, but rather it was something valuable. When Genghis Khan, their leader who united all the Mongolian tribes, gave his worn clothes to someone, this was considered a source of pride for the person because he received something from his smell.
Note: This custom was widespread even among Europeans in the Middle Ages...
Source: websites