OMG. I can’t bear any more shower shoe discussion today. My younger sister picked up a Plantar Wart while studying and living at a ridiculously exclusive and expensive Australian university. My family WhatsApp group has been off the chain this morning with her shrieking about catching a ‘foot STD’ and everyone else trying to calm her down. Apparently the most effective way to kill them is a piece of banana peel with duct tape over the top for weeks on end. I’m going home for Christmas and will be using one of the other bathrooms...
I've got some advice for your sister. Do not bother with the banana peel and tape (or aspirin, or apple cider vinegar, etc.) wives' tales, as they simply don't work on plantar warts.
Living in Japan and constantly walking around locker rooms and onsen I used to score the occasional wart on my foot. Generally speaking, if you catch them when they're small, they're easier to kill. However, plantar warts (categorized simply by their position, usually on toes or soles of the feet) can become particularly stubborn if you let them grow, and even worse, large enough to breed satellite warts around the original one.
Usually, when I caught one of them, I'd use the home cryo-therapy kits like Dr. Scholl's Freeze Away. That's basically an air-duster can with a q-tip on it that freezes, then you hold it on the wart. However, in order for it to actually work, you must ignore instructions. The box will tell you to hold it on for maybe 30 seconds? I'd hold it there for two minutes, or until the tip was no longer cold. Then repeat. Then repeat. That usually killed the wart after two or three freeze sessions. The area turns into a callus, the wart turns black and then it simply falls off.
However, about two years ago I got the plantar wart from hell. I probably subjected it to a dozen freezing sessions and every time it would callus, turn black and fall out...and then regrow again in a few weeks even bigger than last time. It was just set far too deep and I couldn't get to the entire root. After a couple of months of this, I came across a discussion on plantar warts and a number of folks who experienced the same situation as myself swore by a product named Bazuka.
It's basically the same concept as all the other wart killing acid gels, only much, much more potent of a formula. So potent, in fact, that apparently it's not approved for sale in America. I had to go through a UK seller on Ebay to get my hands on some, but believe me, it was worth the hassle.
My routine was every night after my shower, I would place a drop of it covering the wart then set my foot in front of the fan and let it dry. The gel actually hardens into a white scab. The instructions say this is good enough and to just leave it, but I didn't trust that it would stay on for an entire day--plus I didn't want tiny acidic scabs falling off in my bed or socks--so I purchased some of that liquid bandage stuff like New Skin and applied that over the hardened Bazuka gel scab and then let that dry as well.
I would repeat that every night and holy shit, the entire area started turning snow white and the individual wart brown/black, and after two or three night's worth of applications, I'd take a small scissors or pen knife and start picking away at the dead skin. Entire chunks of brown wart would fall out. I think I kept this up for about a month until finally, FINALLY, one day I dug out what looked like the end of the dead brown root and there was a pink hole left. Still paranoid, I continued for a couple more applications until there was no more brown in the white dead skin.
And that's that. No more wart.
I was so pleased I purchased another tube of Bazuka from the same seller, for the next stubborn wart (and it will come, sooner or later) that resists freezing.
And Bazuka is dirt cheap...less than $10/tube. Your sister can thank me later.