One of the many uses of MMO, known since forever, is to prevent corrosion on tools. There is one tool, however, which is probably more severely affected by corrosion than most, but is usually not treated at all to prevent corrosion. That tool is the razor.
Back when the double-edged “safety razor” was the main shaving tool, and some enterprising folks were telling the gullible they could keep their razors sharp by putting them in little pyramids aligned just so, my father told me about something that really did make razor blades last longer. A a man he knew had told him he made his blades last longer by taking them out and drying them off after each shave, then wiping them with a rag that had some gasoline on it. My father pointed out that this would prevent corrosion.
Because a razor’s edge is so extremely sharp, it doesn’t take a whole lot of corrosion to dull it. As everyone knows, moisture promotes corrosion. And the plastic multi-blade razors which have largely replaced the old safety razors, retain a lot of moisture, as you can determine by trying to dry one out after using it. You can whap it on a dry paper towel again and again, and water will keep coming out. Shaking the razor and blowing through it also help get the water out.
Most of the benefit seems to be simply from getting the thing dry, but I then give it a swipe with the corner of a paper towel that’s a bit oily with MMO. I imagine most any kind of oil would do, but I’ve been using MMO as a light lube and penetrating oil for decades, so that’s what I used here.
Experiment has shown that either way—simply getting the head dry immediately, or following up with even the merest swipe of oil—approximately doubles the life of the razor.
OK, even if everybody and his uncle swipes their razors with MMO after drying them off, it won’t boost the sales of MMO perceptibly. But still—it seems to be a case where simply preventing corrosion has a very noticeable practical benefit. Especially if you use those really fancy razors with more than two blades.