Corns on the foot result from too much pressure on that place where the corn is. To eliminate corns, all you have to do is take away that pressure that caused it. Its that easy. A corn or a callus is part of a natural process that your skin undergoes to shield itself. When there is an excessive amount of pressure on an area of skin, the skin thickens up to guard itself. However, if that pressure remains over a longer period of time, then the skin becomes so thick that it can be painful. If that pressure is spread over a broader area of skin, then that is called a callus. If that pressure is over a lesser far more focal area of skin, then that's a corn. The sources of that higher pressure could be many different things like a hammer toe, a bunion or a dropped metatarsal. A proper evaluation is usually needed to identify just what it is that is bringing about that increased pressure and exactly how easy it will be to eliminate that increased pressure.
To eliminate corns totally, you have to eliminate the reason for them. A qualified podiatrist can readily get rid of a callus and corn by meticulously debriding it with a scalpel. However, that corn will return when the cause is not removed. They do not keep coming back because the podiatrist did not remove it properly or for the reason that corn has roots (they don’t). They keep returning for the reason that the pressure that caused them remains. That should be removed if the corns is to be kept from coming back. The way in which that pressure is taken away would be determined by why you have the greater pressure. Perhaps it is as easy as finding a better fitting pair of footwear or it could be as complicated as needing some surgery to take care of the toe deformity that could be resulting in the pressure resulting in the corn.