I use this stuff all the time, especially when I am grinding on my burr king and don't want to use gloves. This stuff will not prevent injuries, but it sure helps with the knuckle shredders that sandpaper can cause.
You just roll it as thick as you want around whatever finger you want... just not too tightly. When I am finishing up the hollow grind of my razors, I have a very bad habit of grinding through the calloused skin to make them bleed. I confuse a bit of heat for skin removal sometimes. It really can become an inconvenience.
So, if you have decided to restore more than 5 razors for the year, this stuff might just be the ticket for you. You do have to keep it from drying out. I keep mine in a sealed container. I have had this stuff as long as 3 years and add a half teaspoon of water to the container every 6 months or so. You can buy it here. If you find it elsewhere for less, be sure to clue us all in.