After harvest, I have about a 5 day window to clean the room, hydro setup, do any mods, then drop the girls back in. The first day, I marinate the room in a bleach and water mix with a pump sprayer. It takes several hours to dry out so that I can re-enter the room. I then stick an ozone generator in there next to a small oscillating fan, close the room up and let it go for about an hour. If you use an ozone generator, make sure to let the ozone dissipate before re-entering.
I've run an ozone generator for a short time in a room full of mature plants with no damage done to the plants. And for experimentation purposes, I had an extra "teen" that I put directly in front of the ozone generator output that suffered for a couple weeks before getting better again. It lost about half of it's lower fans and was stunted for 2 or 3 weeks before recovering. It's now a 6 foot bush mid way through flowering out in my yard.