US Patent 7246628 Method for cleaning floor drains

A method for controlling Listeria in floor drains wherein an aqueous solution composed of a chlorinated caustic material which is soft metal compatible is introduced into a drain where Listeria is present. In a preferred manner, the aqueous solution is introduced into the drain employing a hose end dispensing device having a foam producing nozzle. The resulting aqueous solution has a sufficient viscosity to remain in the drain for about 30 seconds to 10 minutes.