Not that I have any interest in babies of my own, but if I ever had to use the Ferber Method on one, I bet I’d have no problem. (If you don’t know about the Ferber Method, you can read about it here, but basically it’s how you train your kid to sleep through the night, you just let them cry in their crib until they fall asleep, and you don’t give in and go pick them up.)
Well, my cat likes to put me to the test in a similar fashion. She likes to pop out the front door almost every night when I come home, and sit on the front porch. But when she’s ready to come back inside, does she go around back to the cat door, like the other cats do? Noooo, of course not. She sits at the door and meows for HOURS to be let in!

I used to just let her in if I was walking by the front door an heard her, but the hubs was all “don’t spoil the stupid cat, let her let herself in!” So now we just let her meow until she gives up and comes in herself. Although I’m not sure how quickly she’s getting “ferberized,” I can hear her out on the porch from the kitchen when I’m cooking dinner, meowing forever.
Here's a sampling of what I have to listen to on a nearly daily basis. Not only can you hear my annoying cat outside the door, but you can hear another cat inside, meowing back at her!
Oh well, it’s the ignoring part that’s important, not how long it takes for her to give up, right?