These warts are called planters warts, and are caused from a virus. Both of my sons had these, and are in fact very painful. The incidence of these warts for my sons, in both cases, were from wearing wet shoes. If you have a tendency toward sweaty feet, or working in hot environments, it is best to place shoes on a boot dryer, in between wearing or switch shoes off. Meaning, switch one day wear one pair, the next, wear the other. allowing the shoes to dry in between wearing them. Viruses, fungus, and bacteria thrive in a wet environment, thereby setting a advantageous ground for warts to thrive.
That said, what I used topically for my sons was Oil of oregano, and Coumpond W, which is an acid that will "break the outer core" of the wart. Found at http://www.amazon.com/gp/product/B000GCKCVY/ref=as... Compound W Wart Remover, Maximum Strength, Fast-Acting Liquid, 0.31-Ounce
A liquid form that works. Be careful not to get on healthy skin. As I said it is an acid.
Place a drop of oil of oregano, then a drop of compound W on the wart, cover with a bandaide. i did this for about a week, and the wart came off, core and all. If you don't get core and all, it will only return. Oil of oregano is a natural anti viral agent.
Among the other "home remedies" include and used the same way: garlic, bannana peel, and duct tape. Ive never tried these various remedies, but many people swear by them.
For recommendations about other skin problems, and home remedies, go to: http://hubpages.com/health/Natural-Supplements-for...