Corns on the feet are due to too much pressure on that area where the corn is. To eliminate corns, all you have to do is take away that pressure that caused them. Its that easy. A corn or a callus is part of a activity that the skin goes through to protect itself. When there may be too much pressure on an area of skin, the skin thickens up to guard itself. However, if that pressure continues over a longer period of time, then the skin becomes so thick that it is painful. In the event that pressure is over a larger area of skin, then that is called a callus. If that pressure is over a smaller much more focal area of skin, then that's a corn. The causes of that increased pressure could be many different things like a hammer toe, hallux valgus or a dropped metatarsal. A good examination is usually necessary to determine just exactly what it is that causes that higher pressure and exactly how easy it can be to eliminate that higher pressure.
To get rid of corns permanently, you will have to take away the cause. An experienced podiatrist can easily remove a callus and corn by properly debriding it using a scalpel. However, that corn will return should the reason for them isn't removed. They don't really keep returning for the reason that the podiatrist did not remove it properly or because the corn has roots (they don’t). They keep coming back because the pressure which caused them is still there. That should be taken away if the corns is to be kept from coming back again. The way in which the pressure is removed is determined by what is causing the higher pressure. Perhaps it is as simple as finding a better fitting pair of footwear or it could be as complicated as requiring some surgery to take care of the toe deformity which is resulting in the pressure creating the corn.