I've two boys here, one with three verrucas and the other with warts on thier hand.
I've tried freezing them, End Warts (or what ever it's called) and that acid stuff (sorry can't recall right now - Salicylic?). I recall using something called 'Compound W' when I was about 10 I had to apply it daily and it went white and the wart (on my hand) eventually went. I'm presuming it was this acid though
They just WON'T go!
As a footnote (pun intended) there is no free at point of service healthcare where I live. GPs are expensive per visit (dermatologists even more so) but if this is the only solution obviously I'll pay!!