With overhead basking lamps and heating elements to keep our little one warm and toasty the shell gets dehydrated in a hurry. So does the baby tortoise. To mitigate these conditions, daily soakings, daily shell spraying, an enclosure that maintains 80% relative humidity, and a hiding box that further increase the humidity work together to allow the shell to grow as smooth as possible.
To my knowledge, everyone that has followed his advice, starting with a hatchling, has been happy with the results. Others that have started with an older tortoise, a baby or yearling, but adopted the same type of care as he has suggested have had good results.
Depends largely on how they are housed. For my older ones that still have a lot of growing to do, I keep their heated night boxes at around 60-70% humidity, but they walk around in the dry air here all day. This seems to do the trick.