Some lawn mowers such as the Craftsman 37705 have a washout feature. It is essentially a garden hose fitting on top of the circular blade cover. This allows you to pump water into the blade assembly while running the engine. That action is designed to flush dirt and grass debris right out.
Gather what you need First gather your tools and equipment. You will need a power drill eye protection work gloves and a blade sharpening kit. The kit should come with a ceramic blade sharpener and balancer. Expect to pay about $8 for the kit at your local hardware store. You will also need a torque wrench (or a socket wrench in a pinch) and a wooden block. Consider having a rubber mallet on hand too.
To sharpen them secure in a table vise. Now attach the blade sharpener to the end of your power drill. Make sure to wear eye protection and work gloves. Carefully use the sharpener to hone the cutting edges of your blades. Go slowly at first to get the feel of the best angle for meeting the blade and sharpener.