Thanks for the warning and sorry to hear what happened. Were you a smoker? Did you know if you had any parasites? Did you mix the peroxide with Colloidal Silver ?
I stopped the H2O2 (Hydrogen-Peroxid) after a week because I wasn't seeing significant improvement. I'm pretty sure I haven't suffered any side effects as my breathing is no better or worse than before.
Today, I started again but at the lowest dose possible. That is, 1 drop in 5 mL water for about 6 minutes. This time, there was no constriction whatsoever and I'm definitely breathing more easily. So we shall see how it goes.