Dealing with a rusty metal trash can is a common nuisance, but it's a problem you can often fix yourself without harsh chemicals. First, empty and rinse the can thoroughly. For light surface rust, a simple paste of baking soda and water can work wonders. Apply it, let it sit for an hour, then scrub with a stiff brush or steel wool. Rinse well.
For more stubborn rust, white vinegar is a powerful, natural acid. Soak paper towels in vinegar and press them onto the rusty areas. Let them sit for several hours or overnight. The vinegar will loosen the rust, making it easier to scrub off. After scrubbing, rinse the can completely.
Once the rust is gone and the can is dry, consider applying a rust-inhibiting spray paint or a clear sealant to the interior, especially the bottom, to prevent future corrosion. A simple maintenance tip is to ensure the can is dry before putting in bags and to avoid letting wet, organic waste sit directly on the metal bottom. With these steps, your outdoor bin will look better and last longer.