@Mike-And-Jane0 @Gillian166
We spent several hundred dollars for ours, it is big. We borrowed an industrial one from our floors and carpets contractor, and after over a week of his and another the same of ours, we gave up and had the entire place of carpets redone. A tenant had a smelly old dog in there, and when they left, nothing we did short of ripping up the entire house of wool carpeting and replacing it with wood floors would help at all. I've used it in my office foyer when a terrible smell showed up that would not air out. After a few weeks of running it all night, it cleared it up. I think a cat had sprayed. So, I would not count on ozone with carpeting, and if you get better results let me know. I'm never having carpets in a rental again.
@Gillian166 if you have potential plumbing issues, don't wait to get a good plumber. All it takes is a tampon, dental floss, anything with a string, and the entire house can erupt with a backup. I could tell you the experience and the cost, but I won't. A word to the wise...