“Been using H2O2 in my ears for years to dissolve out ear wax.”
I put it in my ears, too, because I think (don’t know) that it reduces the chances of getting colds and flu. There’s that connection with ear/nose/throat, so it can’t hurt.
A cap full of hydrogen peroxide and 3 ounces of water makes a good gargle if you feel like you’re getting a cold.
Be careful not to use too much because it bubbles.