No agreement by an individual to waive, release or commute his rights to benefits or any other rights under this chapter shall be valid, except an agreement to satisfy child support obligations which is being enforced by the department pursuant to a plan under the child support enforcement act, as amended, which has been approved by the secretary of health and human services under part D of title IV of the social security act, as amended, or an agreement between the individual and the department specifying an amount to be withheld as repayment towards an uncollected overissuance of food stamp coupons.