The amount of NOX that you get in ozonated water is diluted heavily in the water so that it is not harmful to mucous membranes, but Nox introduced into an orifice is not significantly diluted and could cause burning of tissue, particularly mucous membranes.
Rectal ozone will deliver far more ozone into the body in a short period of time than drinking ozonated water, even hightly ozonated water with a medical oxygen-fed machine. I just would not use an air-fed ozonator unless I knew for sure the air going into it was VERY dry and I also knew how much the pump was producing in terms of litres of air per minute. It can be fairly easy to overextend the colon with too much pressure or gas volume.
Good antioxidants include Vits A (in the form of beta carotene)C,E K, selenium and SOD (superoxy dismutase found in leafy green veggies, sprouts, wheatgrass, alfalfa powder, spirulina, chlorella etc) There are many others but these are the basics.
hope this helps