Actually the Ninja were quite different than Muslims. They bathed so as not to alert their enemies of their presence during an assassination attempt (think "scent")
ninÂ·ja (nĭn'jə) pronunciation n., pl. ninja or -jas.
A member of a class of 14th-century Japanese mercenary agents who were trained in the martial arts and hired for covert operations such as assassination and sabotage.
I read once that in Iraq if you smell a clean person (soap and shampoo) hit the deck because the only time they bathe is when they're getting ready to go meet the virgins. (That would be a good movie title.)