How do you know when warts have been completely killed off? they're on the foot if it makes any difference

With time: Immediately after with any form of treatment , even if on surface looks normal hpv virus may stay on body with out showing exfoliation , if warts do not appear then can presume are ' killed off' '.

Skin lines: Look for normal skin lines. When the wart is there, the skin lines will stop at the wart. When you see normal skin lines where the wart was at, it is most likely gone.