Yeah, they do break down with time, so it's always worth keeping an eye on the stock. So far I've not seen anyone manage anything with a sacrificial corrosion component, I guess the material is just too reactive for that.
As for the website, they are a small op, even to the point of struggling to ship outside of CONUS, but I've bought from them a couple of times, and their carbide strikers are worth their weight in gold. I've taught many kids how to get a cotton ball going, and a big part of that is just how good their carbides are.