Sometimes it works sometimes it doesn't...I actually had 2 warts, one on each knee, and oddly enough the duct tape got rid of one of them in a couple of weeks...but the other one shrunk then just came back and ignored my duct tape =(
So...I sorta stopped trying for a year or so but I've sprung my duct tape back upon the now unsuspecting wart for another battle.
Anyways, I'll just say that the most annoying thing is really the fact that people will constantly ask you if you've injured yourself, or "what the hell is that" or similar questions. So...the clear tape idea isn't bad.
BTW it doesn't actually HAVE to be duct tape, it's just that duct tape is easily available and sticks pretty well, but it's just the occlusion that'll irritate the skin and trigger an immune response to the area. So, really, any sort of tape will work so long as you can keep it on your skin without it falling off.
I might have to move my war up to include salycylic acid though, cuz this damned wart is really friggin stubborn compared to it's brother.
Warts are pretty random though, sometimes they'll just go away by themselves...I had one on my foot a long time ago and it was hella annoying, and I tried all those salycylic acid patches they had and it just caused my toe to hurt like hell from the burning after a few days, but the wart just laughed it off. Then like half a year later it just went poof by itself.
Hmm...you know, although it's a pretty harmless disease maybe I should try all sorts of random stuff on my wart in case I discover some cure, then I"ll patent it and sue people lol.