I would only use ozone 24/7 in a reactor that sends the flow over GAC to decompose the toxic by products. In that scenario, the dangers are minimized. Otherwise, I'd use very little ozone and only infrequently.
Hydrogen peroxide is a much less effective oxidant, which is presumably why some people think it without risk. It also has a lesser effect for that reason.
Buy my main issue is this: if it breaks down organics, how can it distinguish living tissue from the organics you want to oxidize? Without confining it to a reactor, you cannot.