The recipe I followed was simple:
1 cup blue mouthwash
1 cup apple cider vinegar
2-3 cups hot water
Per the instructions, I soaked my feet in this mixture for a total of 35 minutes. About 20 minutes in, I removed my feet and scrubbed each heel with a pumice stone. Then, I returned my feet to the water for the remaining time and repeated the process again at the end.
Once I'd dried each foot, I slathered them with one of my favorite lotions, Medline's skin repair cream with olivamine that I ordered from Amazon and covered them with fuzzy socks.
Update the next morning -> So here's how they look after the first treatment. I know it's not great, but they are MUCH better than before this Pinterest experiment. You can see where the remaining callouses are starting to break up and slough off. (Gross, I know.) The good news is they are smaller and softer than before this treatment, so I think repeated soakings will be effective. Before the treatment, the callouses extended at least a half inch all the way around my heel and were stained from wearing sandals for so many weeks as I walked dirty, dusty, city streets. So yeah, this is a big improvement.
The verdict -> my feet are MUCH better than they were before I tried this recipe. The heels, in particular, are much smoother, but the callouses are not completely gone. Perhaps they'd be gone completely if I tried this recipe a couple more times, each a few days apart. After the soaking, my feet felt tingly and refreshed for several hours, so that made the experience worth the effort too.
A variation of the recipe is to mix peroxide with hot water and soak your feet in that. I think I might
give that a try too.