For a lot of us amateurs who are growing less than 10 plants, installing an exhaust fan on a room may not be feasible and may give away what we are doing. I think the odor removal machine Flip may be referring to is the homemade one - bucket, Ona and fan.
hearmenow
Firstly I understand what you're saying and I appreciate what you're saying and why you're saying it. It's a fair comment to make, however...
As beenthere says above, investing in an appropriately sized exhaust fan and efficient carbon filter is a lot cheaper and less hassle than spending 5 years in a state penitentary which is what you may be looking at if you do not remove the tell tale odours from your grow area.
I'm not kidding when I give out this advice - these plants can stink bigtime - and they have a very distinctive odour and some strains are a lot more pungent than others. Do you know that LEO's in the USA if they suspect something have been known to stick their noses into someone's letter box to see if they can smell the tell tale signs? I don't want to scare you, but if you ignore this vitally important area you're very much putting yourself at risk of detection.
Odour removal is quite different to odour masking which is what Ona does.
I urge everyone to treat this subject very seriously, the first thing people should do after deciding on their lighting setup is to spend some time considering air exchange and odour removal in their grow areas as this is the next most important area to sort out.
If you cannot install an efficient exhaust fan and charcoal filter setup in your grow area (for whatever reason) seriously consider whether you want to be growing marijuana or not - that's my advice. And I give that advice for your own safety - not mine.