Don't slaves lose loyalty (or gain stress) when you rape your captives? I remember (vaguely) it happening in older version of the game. (That's beside the point that my MC's don't usually rape anyone).
rape is the way to go, you will get mana out of it too, its ok if loyalty is orange (I think?) or green.
it would make sense to use deterrent potion to lower/clear it too, but itsnt implemented yet.
