How it works
Smooth heels in three steps
Your heels aren't dry. They're armoured.
The skin on your feet has no sebaceous glands. It cannot produce its own oil — so it is structurally dry, and no amount of cream changes that.
Under daily pressure it thickens to protect itself. That thickened layer is callus: rigid, and rigid skin splits under body weight. That's the crack.
A cream can't get through the dead layer. A pumice stone gives up long before the layer does. The only thing that changes anything is taking the layer off — which is what a rotating file does in five minutes.