I picked up a verruca at the swim baths a few years back. I tried several treatments including creams and freezing. None worked. I had the verruca for over a year.
I came across an article on the BBC website on removing warts and verrucas. It entailed placing duct tape over the wart, and then filing it down a few days later. Surprisingly it worked.
Here's the procedure:
How to treat your wart or verruca using duct tape
Cut a piece of duct tape roughly the same size as your wart. Then stick it on top and keep it on for six days. If it falls off, cut and stick on a new piece.
On the morning of the 7th day, take off the duct tape, soak the wart in warm water and file off the dead skin with a pumice stone or emory board. Then leave the duct tape off for the rest of the day and night and reapply it the following morning. If you have trouble keeping the tape on, try sticking a plaster over the top of the duct tape.
Keep doing this for four weeks. The key is to keep the tape on your wart for six days at a time, followed by a break of one day. And every time the tape is taken off, remember to file away the dead skin from the surface.