May 16, 2022 · 10 Surefire Ways to Clean Your Rusty Grill. 1. Baking Soda and Lemon Juice. Baking soda will help to loosen any built-up grease or dirt on the grill while lemon juice acts as a natural rust-loosener. Combine one part baking soda with two parts lemon juice in a spray bottle, then spray all over the rusty parts of the grill grate.