Personally I don't worry about it too much, but then again I use vintage blades that almost always have an issue in the pivot area already so, you know, it lasted 60-90 years with the pivot looking a little grungy, I'm not going to worry about a little water in there. But I do make sure it gets some oil in there too.

Now, if I just threw down over a hundred bucks on a fancy new blade, I might think differently. Same if I just spent big bucks to restore an old one.