DS1 is 11. He never washes. If I'm lucky I can force him to have a shower once or twice a week. I have made the odd comment that his hair smells 
He hasn't started to smell too bad just yet but I'm sure it won't be long. However his face is starting to become spotty across his nose and cheeks. More blackheads than spots. However I'm pretty sure it's due to the muck rather than proper acne.
How is one supposed to approach these things. Leave it until he's conscious of it? Wait until the wallpaper starts to peel of of its own accord due to the smell.
Will I just give him a complex?
DS2 has a half hour shower on a daily basis so I think this is child specific.