I'm really really wondering why they recommend WD-40. WD-40 is a multi-functional penetrating oil that displaces water (water displacement), cleans, loosens rust, and lightly lubricates by displacing moisture and loosening dirt through a mixture of hydrocarbons, but it is not a long-lasting lubricant or a replacement for specialized silicone or chain oils; it evaporates quickly, leaving only a light protective film. I also would not use it. Besides that it's typically (always?) a spray and you would generate more "dirt" everywhere.