This is one of the issues I have dealt with. The article states that one way to deal with foot warts is to pour lemon oil on them. I will try it and see what happens.
My SO is trying out Oregano on hers and we will see where we end up. I will keep you up to date.
Author attribution: By André Karwath aka Aka – Own work, CC BY-SA 2.5, https://commons.wikimedia.org/w/index.php?curid=59992