Zap! was specifically designed to clean washable electrostatic furnace filters. It's a powerful degreeser and disinfectant that interacts with the materials used in the Air Care electrostatic furnace filters better than household cleaners. Just spray it on the back and front sides of your filter, and then shoot your your garden hose nozzel (set on strong stream) towards the back of the filter. After you thoroughly punish the filter with a hard stream of water from the back side, flip it over and hit the front side with another wave of water. (Few minutes on each side). Hitting your washable electrostatic furnace filter with this one two punch has been shown to be most effective.
The filters have a little hole to allow the water to drain. Lean then against a wall (exposed to the sun) for as long as it takes for the water to drain and dissipate from the filter. When you replace your furnace filter, turn your HVAC fan "ON" to completely remove any moisture that may still remain on your washable electrostatic furnace filter.
