The State, acting through the State Fiscal Accountability Authority, all agencies and institutions and all counties, municipal corporations, authorities, special purpose districts and other political units may effect the defeasance of any outstanding bonds, notes, or other obligations by depositing in a special irrevocable trust fund, to be held by the State Treasurer or a bank or other financial institution approved by the State Treasurer, obligations provided for in § 6-5-10(a)(1) and monies which will provide the sums required to pay when due the principal of, redemption premium, if any, and interest on the bonds sought to be defeased. Upon the establishment and funding in full of such special trust fund, the bonds so defeased shall no longer be deemed outstanding for any purpose.