Learning to live with shit-head roommates is a chore. I can really sympathize because I lived with nine other people for a year: two had never washed a dish in their lives, several had never cooked a meal before. Which is fine, you know, you can't judge. People come into this world with different resources and in different environments. The lesson I learned though is to not shy away from having the conversation where terms are defined with those with whom you share a living space, like I did for a few months. Take "clean dish". That would seem like a pretty uncontroversial subject, but you'd be really surprised at the level of ambiguity that's supposedly inherent to the idea of a clean dish. Anyways, norm-setting and assertion is key, and assertion is good communication skills. /unsolicited advice