Again, this is not intended to generate ozone at all. (It's just the same HV generator, that could be used to create ozone, if you raise the voltage).
The method is to ionize particles so they are sticking together, which means they can be filtered out much easier. These ionizers do require physical filters to be the most effective.
(But even without filtering, those larger particle are less likely to reach the inner parts of the lung, which makes them less dangerous. I assume, virii sticking together might get damaged and defunct, but this is just an assumption on my part.)