As a BW...I've seen it go both ways. With John it worked like a charm, and one day we just dropped it cold turkey with no problems (can't remember his age).
With Zoe, we did it from the beginning with always one night waking..which mind you is better than two :wink:
At around 7.5 weeks, dh just didn't feel like doing it one night so I said let's just skip it and see what happens. She slept all the way through and haven't had a night waking since
In Zoe's case...I really do feel that the DF was more of an interruption, or that it was "reminding" her to wake up again. I think it's best to go with your instinct. Or just give it a try and see what happens...the worst being, probably an extra night waking. HTH