Summarize the following:
Keep your grinder well lubricated and prevent rust from forming during storage. Fill a spray bottle with food-grade mineral oil. Then mist all of your grinder's metal parts (excluding an electric parts) with an even coat of oil. Pay particular attention to the pusher and screw, since these come into the most contact with your meat as you feed it through the machine. Place each part to your grinder in its own sealable plastic bag. Then add a handful of rice to each bag. The rice isn't strictly necessary, but it will absorb any present and future moisture, which makes it a good idea if you store your parts in the freezer and/or live in an area with high humidity. Mix a tablespoon of bleach with one gallon (3.8 L) of water. Fill a spray bottle with this solution. Then spray each metal part that you oiled before storage to ensure that they are disinfected. Then thoroughly rinse them with clean water to remove all traces of bleach.

Summary:
Oil any metal parts. Bag each part individually with rice. Sterilize oiled parts with bleach before use.