I have watched a lot of TV ads for products designed to soften hands and feet and remove callused skin. They seemed to me to be all the same and were basically grinding away dead skin. I also noticed a podiatrist using a tool that looked a lot like a something I have in my workshop called a Dremel. It's a small battery powered hand tool. One of the attachments is a small barrel shaped sander. It looks to me very much like a round emery board.

Since I'm an outside guy, who gardens, has horses, big dogs and a little ranch that constantly needs upkeep, I have very rough hands. I found that when I put the Dremel on its lowest setting #2, it worked quite well at removing the calluses on my hands and feet. If I turned it up much higher, it caused too much friction and burned.

There is information on the web which suggests it also works on thickened or fungus-infected toenails. I spoke with a podiatrist who confirmed that when a nail with fungus is reduced in thickness and roughened a bit, it allows fungicides to work better because they can penetrate the nail more efficiently and get to the bed where the fungus thrives.

Again, it's very important you know I am not a doctor and am not qualified to dispense medical advice. I am passing on personal experience, Web research and information gleaned from of a doctor of podiatry.