Mix up the toothpaste and salt. I typically like to add a bit more salt during this process, resulting in the concoction look a bit more chunky. From there, simply spread it over the affected area and go about the rest of your day. It's also important to keep in mind that you may feel a slight burning sensation after application. While a little bit of burning is normal, if you find that you're in actual pain, wash the mixture off immediately.
If you plan to reapply throughout the day, simply cover the rest of the toothpaste and salt mixture and throw it in the fridge. The added cooling effect will offer even more relief.
Image Source: POPSUGAR Photography / Murphy Moroney