Ozone is a highly reactive form of oxygen, and is quite toxic.
It might help to sterilise water, as other oxidants can, but I'd be most surprised if it does anything but harm in the body. Oxidants are what anti-oxidants work on -- such as many vitamins. Clean out your body by eating lots of fruit and vegetables, and taking plenty of exercise...
Ozone is a major pollutant at lower levels. It's produced by the action of sunlight on smog etc, and poisons trees, and of course us. The right place for it is very high up in the atmosphere.
Incidentally, the "ozone" reputed to be found at the seaside is imaginary -- it's just the rather similar smell of the salt and seaweed.
There's a very long history of toxic or dangerous things being regarded as good for you. Tobacco, radiation, ozone, mercuric chloride (calomel), arsenic, strychnine, bleeding, purging, etc, etc. Then there are imaginary effects, like magnetism and copper bracelets for rheumatism, homeopathy, "crystals", N-rays (which convinced the whole French scientific establishment for a while) etc etc etc.
As to why we can't just replace what is lost from the ozone layer, I'm not too sure. Several possible good reasons come to mind. One is that it's a dynamic system, with ozone being created and destroyed in balance. The holes are where it's being destroyed too quickly, and if you put more up there, I think it would just go too. Secondly, the quantities must be really enormous, and it's all very high up indeed. How would you transport the millions (hundreds? thousands? billions?) of tons of ozone almost into space? Above Antarctica, too. Thirdly, it's a techie fix, and in the long run those never work!