Reluctant to say this as I don't know your circumstances, but I had similar and forced my husband to take the heavy hand and supervise, the threat of a rough, soapy, flanneling in the shower with the occasional whip of the towel end (playing) seemed to sort him out. As for deo, I am allergic to sprays so they all use anti perspirant roll on 24 hour protection, they all seem to still be in possession of healthy armpits, but miss out on the linx effect, due to me.
The plus side of roll on is I have a spare in the car, so if I quiz them on the way to sports and realise that they are deo- less it can be applied under the shirt easily. They also all have a spare condensed spray deo in their school sports bags, as I don't have to breath it in at school, these cans do seem to remain disturbingly full though.
My overall thoughts, having had the pleasure of chauffeuring five teenage boys around twice a week, when one forgets deo, or has stinky trainers, the others are fairly harsh, I simply open my window to breath.