My parents split up when I was younger, and I ended up with my Mother. Without the dominant father-figure around all the time, my mother and I have faught countless times over everything and anything. She would try to take things away, and I wouldn't care. I wouldn't listen. Always a power struggle. You can't fight the power battle with your son. If you want him to clean his room, you have to persuade him to want to do it. Manipulate it in such a way that he would do it willingly. If he's a teenager, perhaps suggest that girls would not like the way his room is, and that they would want to see it clean. If he learns to clean it up, the women he's trying to attract would like him much more. You can't try and dominate him that way, you have to manipulate the situation into him wanting to do it. That's what my mom used to do to me.