No matter what your problems the solution is simply a stick and a hole, money problem? Don't worry got the stick inside your hole, are you confused wether your gay or not? Try the stick inside your hole! Finally love quarrel? Easy stick in the hole! Oh are having nightmare? No prob put the stick inside the hole
I believe vaginal canal was just part of male omega genital, perhaps it's like female vaginal canal but for male omega the muscular canal extends from their anus (for female it's vulva) to the neck of their uterus (remember this is omegaverse story where men can get pregnant) so basically this canal is a passage to male omega's uterus or it was actually just rectum canal....?
No but sadly there is in fact a real cult with a sex (sacrifices) rituals and people believe it was a passage to the clean their soul and to bring wealth and fortune
It's not a simply spice or just a plot trope to the story i think the author wanted to touch this matter so that people know and aware there's a such a disgusting rituals and cult that exist in this world