I recently bought a new meat grinder and they recommend washing it with hot water, drying it completely, and spraying a food grade silicone to prevent the stainless steel parts from rusting. Can I just use a light coating of oil like I do my cast iron to prevent rust?
Dry stainless steel parts should not rust, and should not need any oil for storage
For non-stainless steel parts, use any food grade oil as a rust preventative coasting. You can wash this off before use
Most meat grinders need a drop or two of oil on the bearing surfaces before you start grinding. Use any food oil you have handy as you will be washing it off when finished
Oil on cast iron pans is not for preventing rust, it's for seasoning - the heat polymerizes the oil and creates a nonstick layer bound to the pan. That's why you don't put oil on the whole pan, just the part you actually cook food on. If you try to oil your meat grinder, it's not going to be bound to it, and you'll just have an oily grinder that gets oil on everything it touches.
the blade and plates are usually not stainless even if the rest of the unit is. I always figured it was because stainless (while harder and better and holding an edge) is somewhat brittle and could flake off from bits of bone. just a thought though.