Humidity from a moist substrate will help, as will soaking. Never use any products on your tort or pick at the skin. Some dry skin is normal, as is peeling as they grow. What kind of tort, what age, and what substrate do you have?
Sand or sawdust are not good substrates and could be harmful. I use cypress mulch. You can use coir, orchid bark, clean topsoil or any number of better substrates. You can get coir from Petco or Petsmart. It comes in an expandable brick. You tortoise needs humidity even if it's a desert type. All tortoises shed but by adding humidity your will shed less. Do you know what species he is?