Dear J.,
I had a similar problem with my son when he was a little guy. I took him to the Dr. and he explained that it's an immunity issue. The body hasn't recognized the wart/s as a foreign body and hasn't attacked it yet. The vinegar, duct tape,and I especially like the idea of the inside of a banana! -I've heard of a wetted aspirin wiped on it too, all work because they irritate the site, but also affirmations work too- the acid brings the body to recognize his wart/s has a foreign substance, so it builds antibodies which take care of the wart by attacking it. I guess the studies show that affirmations also build the immunities and thus can help the body recognize a wart as a foreign substance! Just keep doing what you are doing...it will work- one day you'll look down and the wart will be gone. It's almost like magic! You could also put the duct tape on at night while he is sleeping and it would stay on through the night at least.
Best to you,
H. B. MOM(mother of many-9)