I routinely use h2o2 right out of the 3%bottle to clean wax from my ears. Let it bubble for five minutes and irrigate. Can’t believe it would hurt your nose. Gonna try it tonight if I can get it into an old Afrin bottle.
nasal passages are sensitive membranes...
I am pretty sure an ENT is going to say not to do it ..at least without significant dilution but we will see.
A better solution might just be doing a baby shampoo irrigation which is prescribed for various things by ENTs.