Out of curiosity, is it theoretically possible for a parent company to create a spin off company that holds all of its debt and no assets? Then the subsidiary spin-off company will declare bankruptcy and the parent company remains with only assets.
An arrangement like that (if successful) would be a fraudulent transfer in which creditors could gain access to the assets of the company's to which the assets were transferred, if pursued before the statute of limitations for doing so runs (typically four years from the date of transfer, or one year from discovery of the transfer, in the U.S.). In a bankruptcy, the bankruptcy trustee could exercise that right on behalf of all creditors.
Also, the debt can't be transferred without the creditor's consent. To do the transaction, the assets would have to be transferred to a subsidiary, not the liabilities.