Before you pack up your BBQ grill at the end of the season, clean the grates so next year you’ll be ready to cook! Easily clean the grease and grime from past cookouts by heating the grill for about 10 minutes. Now cut an onion in half and spear with a grilling fork. Rub the onion back and forth over the hot grates until all the grease and grime is gone. This works because the onion contains allicin which is an antimicrobial acid that lifts grime!