i havent had that happen to me(the rpm drops so much), ill take the car to about 6500, press the clutch in shift, and try to go WOT right after i let the clutch out...all that is about .2 or .3 seconds(might be longer, but its just you do it so quick, or u think you are ,you dont really know how quick it is unless you time it) and it drops in around 5k (depending on what gear it is)

plus i think i would just lift instead of trying to play russian roullette with my tranny to get another .3 off my time...