If you want to bring a kid in on the OL but he is insistent on playing another position, unless the position he want to play indicates he's some sort of mental case, (he's 6'9" 350lbs. but insists on being an option QB) tell him what he wants to hear.
Slaton wants to play DT instead of OG? Sign him up at DT. Say he's right and can really play DT ask a coach if they can ever have too many good D linemen. And if he's junk? When he's 5th or 6th down on the DT depth chart and looks over at the starting OG (a 50gal. trash can with mannequin arms duct taped to the sides he'll beg Richt to move him over there. Because ultimately kids want to play and the dollars they pay you in the NFL to play OG are the same color as the ones they pay you when you're at DT.