An ozone generator is much more effective than an ioniser.
I use ozone to 'mop up' anything that might evade my filter - I use very low levels and it works a treat.
Ozone is more dangerous than an ioniser and you must be careful not to be pumping too much of it around. It can burn your lungs at high concentrations......and burn your plants.
They also help inhibit mold and can be used to rid yourself of pests in the growroom if you are able to seal it and vent outside.
I saw your other thread on the DIY suggestion prawn and dropped a bit more info in there - I really would suggest a professionally made unit though.
I do like the comfort of my ozone generator and it is especially useful at harvest time.
Good luck

ETA: info