Not that I will advocate the actions of these men, but think about how desperate you must be to seek that kind of ritual for protection and power. How much fear, anger, sadness, terror, malice, or otherwise do you have to experience in your life to make you feel like you need to rape men for "supernatural powers?"
Curses! The secret behind my power has been discovered! Curses I say!!
Actually, this doesn't much surprise me. After all, they are beset by penis shrinking and stealing witch doctors all the time. Sometimes the witch doctors even turn themselves into animals to escape justice. Awful? Yes. Shocking? Not in the least.