Warts are an immune system that hasn't identified an intruder yet. There are plenty of folk remedies that are basically about tricking the brain into telling the body to get on with it. One involves tracing it and burning the paper.

The last wart I had (when I was younger) I got mad (and angrier) at it one day and started trying to cut it out. I'm certain there were bits of it I missed, but it was gone in a week. I decided I had finally had enough and my body got the message.