SOUNDS USELESS AT LOW CONCENTRATIONS AND DANGEROUS AT HIGH ONES.
Solutions as low as 3% peroxide are used to bleach hair, after all.
H2O2 won't just tackle your fungi, you know? If you take a highly diluted teaspoon of it in a glass of water or something, it probably won't do anything whatsoever, but at effective quantities it will go after gut lining, gut flora, blood cells, etc etc etc. Sounds like a good way of ending up with major internal chemical burns.