Scholl Freeze Verruca & Wart Remover works in a similar way to the freezing method used in hospitals and clinics. Verrucas and warts are caused by a virus. Scholl Freeze Verruca & Wart Remover uses a mixture of dimethyl ether and propane (DMEP) to rapidly freeze verrucas and warts so that the virus-infected cells die. A blister forms and the verruca or wart falls off naturally in about 10 to 14 days.