Most of the auxiliary wiring gutters I have seen installed do not have proper accommodations for grounding (e.g., ground bus bar kit paired with manufacturer-provided flared holes). How would one properly install an "off-the-shelf" ground bus bar in an auxiliary gutter? I would assume some sort of bonding apparatus (e.g., star washer) would need to be installed between the bus bar and the enclosure surface? Would there be a conventional torque spec to use for the mounting hardware?.. Or, if a bus bar may not be used, then how might the gutter be bonded/grounded otherwise?