This apples to the cytotoxic substances as well as the popular caustic salicylic acid. These treatments have shown varying degrees of success, particularly with verruccae which are usually harder than other common warts and have often been abused more and for longer prior to embarking upon treatment. This is moistened and appled to the area for up to two minutes. This can be repeated twice or more if necessary. The method is quick, convenient, effective and safe, provided due precautions are followed to keep the caustic from eyes, clothes, etc.
Silver nitrate is of very low toxicity.
Silver nitrate caustic products are available from Bray Health and Leisure. The Avoca Wart Kit, which contains a Caustic Pencil and all the peripherals such as emery board, plasters etc needed to carry out the treatment at home, is available under the P category from chemists nationwide.