TGTX addendum for amusement—a few years ago, the company claimed to have a non-insecticide treatment for head lice: http://ir.manhattanpharma.com/releasedetail.cfm?ReleaseID=278896 Hedrin is a unique, proprietary combination of silicones (dimeticone [sic] and cyclomethicone) that acts as a pediculicidal (lice killing) agent by disrupting the insect's mechanism for managing fluid and breathing. Hedrin contains no traditional chemical insecticides in contrast with most currently available lice treatments… Because Hedrin kills lice by preventing the louse from excreting waste fluid and by asphyxiation (smothering), rather than by acting on the central nervous system, the insects cannot build up resistance to the treatment.