Just don't hire BA simulator at Cranebank, or it'll be immediately obvious from security records that you've done some practice!
What a curious thing to say. I'd have thought that BA couldn't care less if you hire their simulator to practice for your sim-ride, they want the candidates to do as well as possible.
The only other 744 simulator in the UK is the CAE one at Gatwick (Burgess Hill).
But wait! Your username is incredibly similar to the name of a company that sells simulator preparation rides on the CAE sims at Burgess Hill....