If the machine is in fact a hot corona, wouldn't my mom have experiencing the effects of acid formation, etc. ?
This would only occur if not using pure oxygen as a starter gas. The acids are formed from nitrogen and sulfur in the air.
She says that once she got up to the 20 minute threshold, she has NOT felt any discomfort, at all, doing the ozone. This did not change once we turned up the ozone concentration until we smelled a strong ozone odor. Thus she is doing it at the right dose without any ill effects whatsoever for a couple of months now.
Once the colon becomes accustomed to the ozone, usually after around 3 treatments, the bloating that causes the discomfort stops if done properly.