Refunding bonds may be sold and proceeds thereof may be applied to the payment of the bonds refunded or, as to such bonds as are not yet maturing, such proceeds may be deposited in escrow to be held until such time as the bonds to be refunded become available for payment by maturity, call for redemption in whole or in part (which need not necessarily be on the first available redemption date) or otherwise and during such period of escrow may be invested, without regard to the limitations imposed by any other law, in direct obligations of the United States of America or any of its agencies or in obligations fully guaranteed or insured by the United States of America which bear interest at such rates as to provide funds which, together with any uninvested money placed in such escrow, will be sufficient to pay when due or called for redemption the bonds so refunded, together with interest accrued and to accrue thereon and redemption premiums, if any, and the expenses relating to such escrow, and such refunding bond proceeds or obligations so purchased therewith, together with other funds legally available therefor, may be deposited in escrow with a banking corporation or association which is a member of the Federal Deposit Insurance Corporation, or any successor thereto. Such refunding bonds may also be sold and the proceeds thereof may also be applied to the payment of the bonds refunded in accordance with any method of refunding deemed by the governing body of a governmental unit to be advantageous to the governmental unit, and any escrow established in connection therewith shall be in accordance with the terms and conditions of any related escrow agreement approved and entered into by the governing body of a governmental unit.