My wife has breast cancer and we tried ozone bagging on breast. We were desperate and, apparently, didn’t do things right, so please don’t bash us for that – we’re on our own.

I am not going to bash you.  Bags will work even plastic cups.  I have recommended plastic cups with a hole drilled in the end for the ozone tube a number of times for localizing the ozone application.

She used regular shopping bags and then shwitched to glass bowl for “bagging”. A rash appeared on that area, similar to herpes, and is itching. Is that due to cheap ozone hot corona unit contaminents reacting with sweat? Please, advice on how to deal with it? Should it go away on its own?

The problem is with the type of ozone unit.  With hot corona devices there are sulfur and nitrogen oxides produced that react with moisture, such as sweat forming the corresponding acids.  It is these acids that burn the skin causing the rash.  I had a friend a long time ago who went to someone with a very strong hot corona unit he was using for therapy.  She got burnt really bad where she was sweating under the towel placed to keep the ozone out of her face.

It will heal up on its own.  Its actually kind of like a sunburn.

Something you can try is to make a paste of baking soda and apply over the area before ozonating to buffer the acids.

One more thing.... she has been doing it while breast was painted with Lugol's iodine. Was is wrong to combine ozone with iodine? Please, advice!

Oxidation does affect iodine so I recommend using them at different times.  For example, maybe using the iodine an hour or so after the ozone.