You will want to consider to what level of uncleanliness is your breaking point. You want to make sure you think about your battles and to what level unorganized becomes filth. For example, if your roommate leaves a single dish in the sink and then cleans up later that day, is it worth confronting them over; or if they have been stacking them up all week into a heaving pile of moldy dishes worth a talk? Remember, you chose to live with this individual, so they have some characteristics you appreciate, and do not let something like this get in the way.