This may sound weird to some folks but it works. Within the last year I developed a very painful callus on the ball of my foot below the small toe- walking sewing etc all hurt. Finally had it and took the Peddiipaws grinder to it. If I take the build up down regularily it doesn't hurt. May seem wierd but it works even on rough heals- heck it's just a version of those manual gringers you rub your feet with until you can't stand it