You can do what I did, and this method worked. I had 3 small warts all close together and I put duct tape over them. The duct tape holds surprisingly tight, it doesn't fall off after 1 day like you think it would, but here is how I did it.
For size of duct tape for example if the warts are taking up space about a half inch all together, then cut a piece of duct tape about 1 inch square to easily cover all 3 (or if just 1 wart then use enough to cover that one easily).
You will be surprised that after 4 days the warts are much SMALLER. I dont know why that works but something seems to suffocate the skin and your body just tries to eliminate that area I think, but its obvious how much smaller the warts get.
Just keep doing it for a month or two and they will be gone completely. Bigger warts may take longer I'm guessing.