I got a hard sore on the underside of my left foot & it hurts like the dickens.
Doctor says it is a "corn" & there are medicated pads to put on it from the Pharmacy. I bought some Dr Schols Medicated pads. One with Zinc & the other with ASA.
This has been going on for a couple of months now & the Doctor says it takes time.
My wife just wants to take some of the tools she uses to give herself a pedicure & go to town on my corn.

Any thing worked for you?