It's become a power struggle and he's rebelling by showing pride in his frag choice.
You can lead a horse to water...
[takes off shrink cap]
Have him try Gendarme for a niche starter scent. It's very clean and comforting. Not woody but maybe it'll become his stepping stone to a bigger world. Maybe Tom Ford Gray Vetiver could pique his interest.
Lots of great woody ones out there - Tam Dao, Rose 31 (my fave), Eau des Baux Eau de Toilette from L'Occitane, tons more (obviously)