The traditional Jewish method of negotiating prices; involves stealthy hand gestures and the use of thick dialects and bartering techniques.
A skill passed down through generations of Ninjews, some theologians believe it to have been one of the staples of Christ's teachings AND the primary reason for his crucifixion. The Romans simply could not handle the reduced income across the empire as the number of Ninjew disciples increased.
Today, Jewfu is used only in buy or sell situations. Ninjews are reknowned for their ability to lower the cost of any item or sell it for more than its worth. It is considered poor form to practice Jewfu on a friend or family member.
Hershel went to a coffee shop to get a bagel. Upon realizing the price was greater than he could afford, Hershel used ninjewtsu and successfully acquired the cream cheese for free claiming it had been left out in the sun for too long.