Most of the time I just tear off the superficial skin, but occasionally I tear the skin off repeatedly over several days and it gets really scabby. But it is addictive, once I realize the scab is there, i absolutely positively MUST sit down and tear it off. Once I started tearing off a layer I probably should have let heal, and i realized this once I started bleeding a lot, but half of the layer was off and half of it was on, and I just COULDNT stop thinking about it.