About 6 years ago, the mouth wash world was rocked by the news that ethanol in mouth wash increased the risk of cancer. The theory was that ethanol helped the mouth wash penetrate into the flesh, taking with it the antiseptics like carbolic acid, which may be carcinogenic. That means the ethanol acted to turn the membrane permeable to the more toxic hydrocarbons.
Since then HPV has also been blamed for a rise in oral and throat cancers too.