C.P.
My son is 16 now and he was the same way and still is sometimes. I even asked the doctor about the hygene issues and he said that it will get better once he starts to get interested in girls. He is better now. I think it is almost impossible to get them to do things without nagging. Maybe you should try warning them. Tell them you will give them two or three chances telling them to do their chores but after that start taking privileges away. I have tried doing this and I have also punished him at points. It still happens from time to time but not as much. Good luck!