Whilst chatting in the club the other day the following question was posed; you are in an unrecoverable spin, could you generate enough lift from the flying wing by applying into spin rudder so that it reduced your decent enough to make it survivable?
By "flying wing" I take it to mean the "less stalled wing" as both wings are stalled in a spin, but one wing is in a deeper stall, causing the auto-rotation.
The fact that you are in an "unrecoverable spin" means that the control surfaces, and anything else you can control such as the engine power and propeller pitch, are not capable of arresting the spin. So you can't (as described above with regard to a Cessna 15x) apply power to give the rudder and tail enough effect to arrest the spin.
Since both wings are stalled, neither is generating lift, so you are basically a rock.
If you were to decrease the stall significantly in the lesser stalled wing, to the point that it was creating lift, which would slow your descent, you would, by definition have arrested the spin. But you're in an unrecoverable spin, so that's not possible.
So the answer to your question is no, you can not make it 'survivable' because you can't create lift in a stalled wing unless you un-stall the wing, and that, again, would mean that you're no longer in a spin.