A episode of the current season of the UK TV show QI put forward the following:
When the Vikings invaded in the 11th century, English women found them attractive because they washed more often than the native British men. The Vikings tended to come without women, so they married English women, upsetting the locals. One monk, John of Wallingford, claimed that Danes cheated by washing. He wrote: "The Danes made themselves too acceptable to English women by their elegant manners and their care of their person. They combed their hair daily and took a bath every Saturday, and even changed their clothes frequently, be which means they undermined the chastity of the wives." Thus there is a theory that all of that stories about Vikings raping and pillaging were written by Englishmen whose wives were taken by more attractive Danes.
I must remember to have a bath on Saturday to make myself irresistible to women.