Well, not to get into a pissing fit, but no...not quite....Double clutching is a way to more precicely rev match, but it is not needed. I can rev-match a car without ever using the clutch, you literally rev the motor to the rpm where going into a given gear and put it in gear, no clutch needed if properly matched. Not the easiest on your synchro's but it is do-able.
Double clutching is a method used to more precicely match revolutions whereby you push in the clutch, take the trans out of gear, let the clutch out, rev to the appropriate rpm, push in the clutch again and select the appropriate gear.
In modern synchromesh transmissions this is not necessary. The synchro's are there to do the synchroizing for you. Simply push in the clutch, pull trans out of gear, rev to appropriate RPM and select gear and let out clutch. If your transmission is healthy with good fluid, and you don't ask too much of it (I.E. trying to select 2nd gear moving at 60 mph with the engine at idle) then you should have no problems.
Actually try double clutching on an Auto-X course, and you'll find you're slower and asking waaay too much of your feet, especially in the corners where you've got to heel-toe your downshifts and still double work the clutch all in time for a corner coming at you at 30 mph with only 30' to react...Doesn't work, and I've yet to see a national level driver try it for exactly that reason
Laters
Ryan