E.M.
apple cider vinegar and duct tape. it'll take a while....and you want the really sticky, cheap duct tape.
use a cotton ball (the one time I don't use rags..I don't want to transfer this virus to anything!!!) to wipe apple cider vinegar on it. let it air dry most of the way (my daughter was pretty impatient, so it was only a minute or so), enough that duct tape will stick and then cover with duct tape - a big enough piece that it covers it and stays on. repeat daily for 4-6 weeks.
it it's really big, it may take freezing by the doctor (i've never gotten those home kits to work) and then followed up w/ the duct tape routine.