Getting confused over O3

Recently dad asked me to look into getting an Ozoniser or Ozone vegetable washer for him. Was checking around the web to see what is available on the market .... which is very little if we are just looking at Singapore. Well, there are suppliers, but many of them, in my personal opinion, look a little dubious. Afterall, it just doesn't feel quite right ordering a product from someone who operates out of an HDB flat.

Besides, all this craze about the benefits of Ozone... is it for real or just marketing talk. I can't help noticing the discrepancies between product claims and medical research reports (that ozone is safe at 0.05 ppm or something like that). Most products don't even mention ppm...

So how to find a safe and right product? Is it necessary at all? I wonder.....