I've got totally mixed feelings on this but here goes, I'm sure that anyone that want's to learn I can get them to hit a 6" bull @ 20 in an afternoon sesion with a good compound that and a week worth of guidance should get him inside of 4. IF (big IF) you can convince him to limit his shots to inside his effective range then maybe. Sort of sounds to me like he's a spray and pray type and if that's the case you won't be able to convince him at all, so I would agree with your NO decision. In the end it's your choice and your call, good luck with it.