Not sure if this is just an old wives tale, but....
First thing in the morning, as soon as you wake up, before you get out of bed / have a drink / go to the loo, lick each of the warts (or in any case put your saliva on them). The healing properties in the saliva destroys them.
Sounds very wierd, I know, but I do know people that it has worked for. And it won't cost you anything. Try that for a couple of weeks first to see if it works before you spend money on lotions and potions!!