SASless is correct. Here is thee controlling sentence:
The applicant bears the burden of clearly and convincingly demonstrating that the supplemental passenger restraint system can be quickly released by a passenger with minimal difficulty and without impeding egress from the aircraft in an emergency. In reviewing any such application, the FAA shall consider the design, manufacture, installation, and operation of the supplemental passenger restraint system.
As far as I am aware, there are no FAA approved harnesses.