The reason is because superstition is the cornerstone of most brainwash systems of religion.

The reason they are so insistent upon cleaning before praying, is because the Boogy man, likes ka ka, and having ka ka on your body while praying leaves you vulnerable to the Boogy man(aka the devil).

Mass control method and superstition at work. A clean arse is a no brainer, but having the religions tell you exactly how to wipe, is just cradle to arse to grave mass control.

Create the Boogy man, make followers afraid of the Boogy man, then dictate every action for fear of the Boogy man.

Ugh. They are hopeless...