During the Mongolian Empire, people did not believe in washing their clothes, or themselves.

They refrained from doing this because it was their traditional belief that by washing, they would pollute the water and anger the dragons that controlled the water cycle.

Therefore, clothes were often not changed until they fell off or fell apart, except for holidays when specialized robes were worn. Because of this, the smell of the outfit was seen as an important aspect of the wearer.

For example, if the Great Khan were to give his previously worn clothing (with his smell on it) to a loyal subject, it would be considered a great honor to have not only the clothing, but the smell as well.

[link to en.wikipedia.org]

the Dragons did not want Mongols stinky asses

in their water.