From what I've read: Ionizing the particulates in the air is akin to statically charging them.
You're not "purifying" anything, just sticking the particles to the nearest surface, like a child pulling off booger from their nose.
This also probably explains why more dust started sticking onto the car dashboard ever since I started using an air ionizer.
Now imagine if you get toxic particles and allergens coating your walls. That's just a ticking time bomb.
You'll do much better with an actual HEPA filter, which stores all the particles that's filtered, in an actual filter.
TibblewinklesTo add to this: A better combo than ionizing purifiers is indeed a HEPA filter *AND* a humidifier. If you keep your humidity at ~50%, you'll find that HEPA filters will do a considerably better job at catching dust particles. You'll also breath easier and get less nose bleeds in winter, I've found.