Bazuka Sub-Zero is a home use ‘freeze’ treatment for verrucas and warts. Based on the cryotherapy method used by doctors and healthcare professionals, it works by quickly freezing the verruca or wart to the core in just one treatment. It may be more suitable for stubborn veruccas and warts, and when a really rapid treatment is desirable. Bazuka Sub-Zero is not recommended for children younger than four, because the sudden freezing process can be uncomfortable.