★★★★★
What worked for me was lemongrass essential oil diluted into a carrier oil (best is squalane but maybe any will work). How dilute to make it depends on how sensitive your skin is, which partly depends on how bad the fungus is. At first, make it pretty dilute, like maybe only 20% lemongrass oil. As your fungus goes away you will be able to increase to 60% or even 70% lemongrass oil.
Apply it 4 times daily or more. If it burns like hell then dilute it more. It should burn just a little bit if your fungus is bad.