So for this, are you going between the legs and spraying up or behind the butt and spraying down? How do you get the water to spray your butt without dripping/slashing poo water on the nozzle or your hand? Also, how do you avoid blasting your balls?
https://baniamechta.com/smesitelni-baterii/smesiteli-za-banja/higienen-dush/
the bulgarians call them "hygiene shower"
Discussion
think like shooting yourself in the arse with a pistol. behind your back and pointing downwards towards the toilet bowl. thus the name 'butt gun'
Practice, I would imagine.
oh, also, the spray is pretty narrow beam like a gun, so it doesn't hit much other than what it's pointed right at.