is not charged there is no fluid flow each of these solenoids is preferably controlled by a microcontroller not shown a single microcontroller can be used to control each device or one or more devices can have a dedicated microcontroller the microcontroller is adapted to generate and output signals used to operate the solenoids the microcontroller is preferably programmed to activate and deactivate the three solenoids in a fixed sequence with a specific time duration for each for example a cycle can comprise a pulse of fixed duration that charges the polycationic solution solenoid 50 followed by a pulse of fixed duration for enabling the rinse fluid solenoid 54 followed by a pulse of fixed duration for enabling the polyanionic solution solenoid 58 followed by a second pulse of fixed duration for the rinse fluid solenoid 54 preferably the microcontroller is programmed in small time intervals such as 10 milliseconds so as to produce pulses ranging in duration from 10 milliseconds to many seconds or minutes similarly the duration between the deactivation of one solenoid to the activation of the next solenoid is also programmable typically within the same ranges as stated above while the preferred embodiment enables one nozzle at a time the invention is not so limited through.