Can I demand the return of our product that the debtor has in inventory to satisfy an outstanding and seriously delinquent debt?

Answer: You can ask the customer to return the merchandise voluntarily. Please keep in mind this is not your merchandise. When title to the goods transfers from the seller to be buyer, the merchandise belongs to the buyer. At that point, absent a security interest, the goods belong to the debtor company. The debtor can voluntarily agree to return them, but you cannot require/demand/insist the merchandise in stock be returned to you.