You can definitely do a pure run even on prisoner difficulty. Besides knowing what edicts are actually good and being able to properly dodge enemies on the way to the boss, it's all about focusing on the mind stat. Once its high enough, it doesn't even matter how 'strong' enemies are, because even when Karryn runs out of stamina, if her desires aren't high enough for groping, everyone will start jacking off, defeating themselves. This way you can sort of cheese yourself out of difficult situations by just laying on the ground, spamming 'lower desire'-skills and waiting for the enemies to finish. This also avoids Karryn getting too sadistic and building pleasure from defeating erect enemies.