Calloused Feet

One of my friends has feet that are badly calloused, he used to hike a lot (every weekend, 4-6 hours), and now he can not because he hit a nerve. Now if you look at his feet, theres a piece of skin with a swirly dot in the middle, I suspect to be the nerve. He wants to continue the hike, but says he really hurt when a rock, sand, or the branch it stirs. What can we do to cure?

My husband ... should say was ... very calloused feet. A week or two using the PedEgg and his feet are awesome. I bought it for $ 19.99 at Walgreens, but I see now (it appears) they have at Walmart for $ 9.99. I do not know if this will help a bad nerve or not, but surely help calluses.