sorry for the delay for some reason I'm not linked to this thread.
get one clay bar and cut it into 3-4 pieces. As the piece gets dirty move on to the next clean piece. Depending on how bad the car is you should be able to get 1-2 uses out of each piece.
Nothing really special about the application.
Here are Menzerna products in action with the PC:
http://paintcare-n-detailing.com/menzerna.html