I had a small wart on my little toe for about 4 years, I picked at it, cut it off, but it always returned and would get rubbed and become sore.
I had read on the net that duct tape will kill warts. So I tried it. I put a small piece over the wart and after about 3 or 4 days it became unstuck, so I replaced it with another which in turn came lose in 3 or 4 days. Then I waited. After a few days, I noticed that the whole area around the wart looked dried out.
So I picked at it. The wart just came off leaving a crater. It has not returned yet. And it has been about three weeks. There is no trace of there ever having been a wart and the skin appears normal.
Over the past 50 years, I have enjoyed liquifying my occasional wart using concentrated nitric acid and a toothpick. There is something satisfying about watching a wart painlessly disappear before your very eyes, but some warts are not easy to get at with acid without burning your skin. Liquid nitrogen is worse than useless, acts like fertilizer on them.