When I was in highschool I was prescribed Acutane for 6 months, worked a wonder, truely! As for over the counter or in store products, SpectroJel is a great topical cleanser that doesnt dry out the skin. Also another key factor is sweat. No joke, make sure he gets a good sweat in regularly, it opens the pores right out, if he can then get a good clean/rinse in with the SpectroJel mentioned above and some sort of exfoliant it will really help.
But above all Acne is hormonal, so if it is severe I would recommend at least acting your doc about something like Acutane or other ingestible treatments!