I had a plantar wart on my foot for about 5 years, it was so big a callous formed over it! But I can say after trying this and that I finall got rid of it and its 5 off-spring! Here's what i did... mind you, if you try this BE VERY VERY VERY careful..
1. soak your foot in warm/hot water till the skin softens.
2. use a pumice stone to GENTLY remove the top layer of skin from the wart
3. towel dry your foot - don't rub, blot only and I always used paper towels so I could just throw them away and not worry about spreading the wart to other areas of my body (call me paranoid)
4. apply a somewhat thick ring of vaseline around the wart but not on or over the wart, just to protect the non-wart skin.
5. wearing latex gloves, dip one end of a Q-tip in 35% food grade hydrogen peroxide... not 3%, not 10%, must be 35% (I tried them all)
6. put the moistened Q-tip directly on the center of the wart... it will trun the skin white and bubble a bit.
7. after about 15 minutes (when the peroxide has dried) you can put a sock on and go about your business as usual.
The next day when you do this, DO NOT soak or pumice your foot, but when the time is right, and you'll know, you can cut away some of the skin with a cuticle clipper or nail clipper - just make sure it's sterilized and never use it for anything else -- those pesky warts spread like wildfire)
Apply the peroxide once or twice a day (trust me, no more than 2x per day), the first couple of times it wont hurt, but eventually, I assure you, it will give you a "walking on hot coals" sensation for about 10 minutes. If it hurts too much, run your foot under cool water, this will neutralize the peroxide.
It will go away... and when it seems as though it's gone, use the peroxide for another week but only once a day... there will be discomfort when the peroxide is applied, just try to keep it on there for about 5 minutes before running it under cold water.
It worked for me... and most importantly, from the first time i applied it, I could tell it was going to work.
You won't need much peroxide at all just be VERY VERY VERY careful with it... it is an oxidizer and can burn you very badly, but then again, the salicylic acid you buy in the store can do quite a number on you too, at least the peroxide works!