I don't see a second OWB in the diagram Mountainman posted.
I think I understand what you're saying, though. If the second gear rotated on a reverse-direction OWB but still had a centrifugal pawl to lock it onto the output shaft at high speed, then the reverse-direction OWB could transfer reverse torque to provide braking when the centrifugal pawl would normally start ratcheting instead. That seems like a plausible setup, though I don't know how long the OWB would last before wearing out. Ideally OWBs should always be used in combination with ball-bearings to support lateral loads and to keep the OWB perfectly centered on the shaft, but that doesn't seem to be how RC companies use them.