Wow, I figure that one would have been answered years ago. I mean, they've already figured out the proper way to wash your private parts, right?
"wash your private parts"
In one of Khomeini's books of his philosophy ( I have a photocopy of the out of print English translation) , he gives detailed instructions of what a man should do after urinating, even down to details of which fingers to use to hold which part of the penis and how to pinch it where.
After the revolution every copy of this and a couple of his other publications were bought up all over the world and made to disappear. The Persian language ones were already a bit cleaned up but the original writings in Arabic are hilariously mad with details of what to do with your wife if you slept with a sheep first and then wanted to have sex with her. Including which foot to place first into the toilet where you would do the necessary ablutions.