Yes, you can use a wire brush to clean the grill grates after each cooking session, but make sure to remove any stray wire-brush bristles before firing up the grill, as using wire bristle brushes can be harmful to your health. The brush’s wire bristles can break off, remain on the grill grate, and end up in the food you’re cooking, so you should use stainless steel brushes, which come in both bristle brushes and bristle-free styles and can be used on a hot or cold grill.