What's "unnatural" about chlorine? It's all over the place--the ocean is FULL of it--it's called SALT (NaCl) and salt is used in SWGs to make....CHLORINE, which, when it's used up, recombines BACK into ...Salt.

Ozone is a deadly poison and ozone generators are either 1) Ineffective or 2) extremely dangerous high electricity users.

I don't know how you can get greener than a SWG unless you have a wind generator to power it!