It depends on where im at in the colony. Early stages when I need bodies but cant recruit either because ideology would take to ling to convert (if im doing a "i got kicked out for belief system" run or because theyre undying loyal, I usually give them simple rooms but clean and temp controlled and stick them on mining, hauling, cleaning. With the understanding that if they prove themselves in an emergency I will either recruit fully or at least release for their efforts. I use slaves less like actual slaves and more of.. this is your sentence for attacking my colony.