you know what i'm gonna do in that scenario? i'm gonna open my eyes, and look up. then i'm going to pull up and to my right while making sure i'm not going to hit someone above me as i'm doing so. that's gonna reduce the closing speed and give me more time to spot the traffic. if it's really desperate, i'll pull my water (if i happen to be carrying any) to increase my visibility to others until i think the danger has passed. use every resource you can and get creative. no amount of anything besides a forcefield can eliminate two aircraft from rubbing. i accept that every time i get in. I also accept that flarm reduces the risk significantly.

Consider when programming your brain Andy- Almost everybody, when faced with the head on scenario will likely do what you mentioned. Sooooo- a better scenario is to push and no banking as it likely will increase your projected cross section.
Matching the other guys bank is best obviously. In the real world you will never think about water dumping. The emergency will be over before your brain gets to that.
FWIW
UH