Very much enjoying this discussion. However if by using the mixture you do have an incedent and the the infamous CAA get involved I think that they may quote AIC 52/1999 at the board of enquiry.
6.3 Piston Engines
6.3.1 Generally the throttle may initially be moved smoothly to the closed position; the mixture control or Idle Cut-Off should not be used to simulate engine failure. Reference to the engine manufacturer's recommendations should clarify the technique in particular cases. When the trainee has identified the 'failed' engine and completed his 'touch only' feathering drill the throttle should be advanced to the zero thrust position.
I throw this in to continue what is a lively and interesting discussion