Nigel
I think you've missed the point of my and other posts. The OP asked about what could be used to indicate spin direction. The recovery procedure is, as I and many others have stated, indicated by the POH. If that doesn't work you had better know some more spin recovery tools and, for example, letting go of the controls will do you no good if active control input (suggested by POH) has not broken the spin. On the other hand, and if letting go does not break the spin (if suggested by POH) you had better get active. The rudder is one of the most powerful anti-spin devices and you had better know which way to push it. The problem is that after several turns you may be so disorientated that you really can't tell which way you are spinning and may not be able to see the TC (nystagmus?). Then your best bet may be feel of the aircraft rudder pedals. As in all things flying YMMV, but knowledge imparted is more valuable than ignorance. A good pilot should try earn beyond the knowledge level of his original instructor (some may know little more than the teaching syllabus) and it was quite appropriate for the OP to ask and get opinions that are posted here. While I disagree with some statements posted in this thread I, personally state when my knowledge is uncertain ("I think").
Please note that I was not advocating just pushing the rudder as sole spin recovery technique but simply answering the original question. I suggest that PARE as the optimal generic spin recovery technique and NASA says the same, as does the CAA. (
Handling Sense Leaflet 03: Safety In Spin Training | Publications | CAA). OK?