the shell cream isnt for aesthetic purposes, its actually therapeutic. hell id love to not do it, becuz they used to really hate it. that equals clawing..lots of clawing..besides, its a big time-eater..and they still sometimes claw..
it establishes proteins and oils that are necessary for the turtle's shell to maintain its natural elasticity (for lack of a better word). basically, its like hair conditioner for humans, but with the ingredients to condition a turtle shell.
umm..to further clarify my previous reply, a balanced diet shuld take care of that shell. if its urgent i suggest shell cream, but u still need to check the diet, check for calcium. if there isnt enuff in his diet, crushed cuttle bone always helps.