As a stockholder in the WD-40 company, it pains me a little to write this, but there's a better household lubricant available: Boeshield T-9. The formulation was developed by Boeing, and its unique combination of solvents and waxes is designed to pentrate metal pores and dissolve minor corrosion, then leave a resilient waxy coating that lasts for many months, displacing water, and preventing corrosion. I bought it as a lubricant for my bicycle chain and gears which got super rusty over the winter — and its superiority to WD-40 was apparent, both instantly in the amount of rust it dissolved, and over the longer term, as it has kept the chain lubricated. (And the waxy coating repels not only water but dirt and grime too, another superior trait.)
As a houshold lubricant, you'll find a zillion uses for it: Cars, trailers, bikes, hardware, tools, outdoor furniture — in addition to the more specialized marine and aerospace it was designed for. Find it locally at REI, West Marine or Sears, or buy Boeshield T-9 at amazon.com. It is not safe for use on food-preparation equipment, and should not be used as a personal lubricant. If you're looking for that, check out Liquid Silk.