I would say semi. If they have never played before then let them focus on the game and not the gun.
Also, Would it be a safe bet that most of them wont play again or wont make paintball part of their regular routine? If so, Let them blast away and have fun "shooting like Crazy!"
I have seen renters at the local field having almost as much fun shooting at the crono station than playing the game...Sometimes its all about shooting stuff.