I was recently in the same position as your brother, and I ended up with a hole in my foot. I thought that it might be to ebut when I apply a little pressure righ beside the hole there is still lots of pain. I wouldn't advice putting the oil inside the foot. I went to this site, and brought this product that completely cured it. however prior to that I tried ducktape. The duck tape smothers the plantar wart of oxygen and kills it. however it didn't kill mine, but it took a lot of the pain away. The site that helped is http:www.howtocureplantarwarts.org