Rust removal 

Scrubbing:

• Steel wool 
• Black sandpaper
• Steel brush

With a lot of rust it is recommended to start with a wire brush or steel wool to do the coarsest work. And only then switch to black sandpaper. That way you won't scratch your armor. After that you can also polish it with toothpaste to remove scratches.

For smaller items, such as:

• jewelry
• knives
• hand tools

You can use white vinegar. Let it soak for at least 10 minutes. You can polish it afterwards with toothpaste.

This technique can also be used for larger items. In that case, dip a cloth(s) in white vinegar and wrap it around the item.

This method is best suited for items that are more fragile and require a careful approach.