I have spoken to a Dr Med - who has warned me against using Hydrogen Peroxide (H2O2) in my airways! H202 is a strong oxidizer; is often used as a bleach or cleaning agent. (Concentrated hydrogen peroxide, or 'high-test peroxide', is therefore used as a propellant in rocketry!)
So my message is: do NOT use H2o2 unless you have consulted your Doctor first. You could do serious damage to your airways! If you are not sure, Read this: http://en.wikipedia.org/wiki/Hydrogen_peroxide#pH_of_H2O2