It is true that ozone cleaners basically work by dropping particulates to the floor, furniture, etc. (I used to sell air cleaners, and have owned several brands). The air may be (or at least *smell*) cleaner from the ozone, but the "dirt" is still there. If you have small children (and/or ferrets), they are crawling around on all the smoke, dust, etc, that the ozone cleaner dropped out of the air! And it is also true that high amounts of ozone are suspected of being hazardous to humans. Filters may be a nuisance and expense, but only an air cleaner with a filter truly *removes* dirt from the air and the room. There are air cleaners available with electronic, washable, permanent filters -- I have an Oreck air cleaner in both my family/ferret room, and our bedroom. There are other brands out there, as well. As much as I love my fuzzies, and as often as I clean their living space, I need the air cleaner to make our house not smell like "wow! you must have ferrets!" Joanne I'd rather be in a boat with a drink on the rocks than in the drink with a boat on the rocks! [Posted in FML issue 3154]