Islamic Houri is about 72 virgins, not seventy, and it's not just for martyr's, it's for any Muslims that lives a good life. That particular belief is the same thing as Christians believing they get a halo and wings to float around with in heaven after they die.
The spoof is so subtle, it's not linked in any way, shape, or form, other than in your bigoted mind.
“Seventy versions†sounds like a subtle spoof of Islam promising ‘seventy virgins’ in the afterlife for the Muslim that will work himself to death by strapping on explosives and blowing himself to kingdom come.