Sounds like something out of Monty Python Holy Grail:

Then, shalt thou count to three, no more, no less. Three shall be the number thou shalt count, and the number of the counting shall be three. Four shalt thou not count, nor either count thou two, excepting that thou then proceed to three. Five is right out! Once the number three, being the third number, be reached....


And it is not a superstition that the number of times to be washed as to be an odd number?