Examine the trash chute and make sure there are no obstructions. You should go floor by floor to determine that there are no blockages; several apartment and co-op managers who spoke with Cooperator.com have had experience with residents sending bulky items like furniture down trash chutes.
If the way is clear, a chemical wash is sprayed on the sides of the chute to loosen the collected gunk. Most professionals use a biodegradable enzyme spray to begin the cleaning process. This enzyme not only will loosen stuck-on garbage, it will break it down into smaller components for easier removal.
Professional cleaners say you should begin at the top floor and work your way down.