https://www.hindawi.com/journals/ecam/2021/5592042/
They used hydrogen peroxide to successfully treat the signs and symptoms of patients diagnosed with COVID-19 [9]. They base their treatments on a combination of oral, intravenous, intramuscular, and nebulized hydrogen peroxide. Their approach has resulted in zero deaths and the recovery of 107 COVID-19 patients [9].
you can add OTC peroxide to your water.
A nebulizer is inexpensive to buy.
you don't need to buy food grade peroxide and dilute it like some sources say
Wound care saline solution comes in a pressurized can and stays sterile at room temperature (contact lens saline is bad to nebulize... it has preservatives. Wound wash does not.) An insulin syringe is otc (you may have to sign a register) and each "unit" is 0.01cc, making an easy measurement in the nebulizer cup. 3ml saline to 3 units hydrogen peroxide is a conservative dilution. Bad dilution is dangerous, but proper dilution is not difficult.