Did you ever decide what you'd like us to call you?
You don't need to apply any topicals to your tortoise. Not to his shell, and not to his skin. He gets along just fine without any. You can gently scrub any dirt off with a soft bristle brush after you've soaked him in warm water.
If you are noticing what appear to be dry skin, please don't worry about it. Tortoises, like all reptiles, shed their skin and sometimes it comes away in bigger pieces than others. Don't pick or pull at it as you might make your tortoise sore. Any loose skin will rub off naturally.