I had a spot about the size of a quarter of some kind of skin fungus but not on that area, on my butt cheek to be plain.
I went to 2 or 3 doctors and everything they gave me to put on it made it worse.
So I went through the kitchen cupboard trying everything. I don't even remember all what I tried but I did try peppermint oil (OUCH but didn't work) and clay, didn't work, made it itchier IIRC, and some other things. I did not know then what I know now about natural healing methods. Nothing worked until I got to vinegar. Put some on and WOW it stung. Next day, almost gone, in about 3 days, vanished. I had had it for months and months.
It has also since cured other peoples' weird fungus skin rashes. I have used rice vinegar, wine vinegar and white vinegar, I am sure apple cider would work too.