Ozone is useful in breaking bounds of compounds. I use both a low grade ozone/negative ion gen and also have a shock ozone generator for major purification fast. The latter is never used with people, plants or animals present. It dissipates quickly after a "treatment."
Wouldn't be without either in this toxic day and age.
I also have an ozonator for use with oils and water. Different reasons for owning that one. ;-)