Here's another promising treatment for COVID-19 that used injected ozone into the bloodstream to combat the virus. Airborne ozone is deadly to the virus, however it's also harmful for humans to breath. Infused into liquids, such as water it's not harmful.
https://www.ptcommunity.com/wire/texas-right-know-calls-us-consider-covid-19-ozone-therapy-after-it-shows-promise-italy