if you take a look at the underlying principle of ionizer machines you will find that it does not remove any particles, but makes them cling to walls, curtains etc until they loose their electrical charge and let go, to be either breathed in or ionized again.
if you want proper indoor filtration go for a IQ-Air filtration system.
Yes, they are expensive, but they actually do what it says on the box, as opposed to a lot of other products.