I have also seen some cheap inonizers that are essentially a high voltage, miniscule current DC power supply. This is applied to needs olr plates or whatever. Line operated units typically used diode/capacitor "ladder" multipliers. I have a cheap unit in my car that is essentially the guts of a CCFL inverter with a cap and diode on the output. This voltage was applied to a mesh wrapped around the outside of a small NE-2 sized blue neon bulb, which had it's leads grounded. It emits a small amount of Ozone, and it manages to remove the stale smelling "Caravan Musk" without adding any "canned new car scent". And the Blue light adds 5 horsepower! It does provide for interesting conversations with passengers on just how useless it is.