Babywise or Baby Whisperer

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Hi ladies!
Has anyone started the Babywise or Baby Whisperer method at 12 weeks? What kind of success did you have and how long did it take? I'm going back to work in 3 weeks and my LO is a bad napper and can't fall asleep independently. I needs get him on some sort of schedule so we can get to bed at a decent time and wake up for work! Thanks!