I have to say I agree with Krang. My DS is 4 months old and after about 10 weeks started sleeping through the night a handful of times. On the other nights, he'd wake up maybe once or twice in the night but would settle back to sleep again quickly with his dummy.
A week ago he started being a complete nightmare, waking every hour during the night. There was little point in using his dummy to soothe him back to sleep as he now pulls it out of his mouth (but can't always put it back in again). DH and I were shattered on so much interrupted sleep.
I really don't condone CC but in desperation, I agreed with DH to give it a try. But I decided to start during the day rather than at night - less stressful for both myself and DS. DS has always been terrible at sleeping in the day, catnapping on and off, which DH and I felt was part of the reason for his unsettled nights.
I have always used a dummy and rocking to get DS nice and sleepy before gently lowering him into his cot. Yesterday I laid him in the cot wide awake (no dummy), kissed him and told him it was "sleepy byes time", then left the room. Immediately he started to grizzle, but I made myself wait two minutes before going in. I leaned over the cot so he could see me, said "Shhhh, sleepy byes time" again and then tiptoed out. He grizzled for about 30 seconds, then went to sleep. During his lunchtime nap he woke twice more but quickly settled back to sleep with a quick "Shhhh, sleepy byes time" from me.
Usually he's a nightmare when I put him to bed after his bath, and it often takes 45 minutes to an hour of constant trips upstairs by me or DH to pick him up, soothe him and settle him back to sleep. Last night, he cried for two minutes, so I went in and used the same method as above. He cried for another two minutes, so repeated the same. He then went to sleep and stayed asleep until 9:30, when he made a couple of noises then settled himself straight back to sleep.
Woke him at 10:30 for his last feed, and he was back in his cot asleep by 11:00. He went straight to sleep with no need for any settling. He then slept right through the night and was awake in his cot playing with his hands at 6:55 when DH went in to get him up. He greeted us with a huge grin so he wasn't in any way distressed. In the night I heard him making noises at about 5:30 (the time he usually wakes up, wide awake, and won't go back to sleep) but he settled himself back down without either of us having to go in.
I am still cautiously optimistic as it could all be a fluke, but fingers crossed! I feel that DS was actually perfectly capable of settling himself down but because we always rushed in at the first sound, he never got the opportunity to try. I haven't even used his dummy for the past day and a half.
I would never have left him to cry indefinitely, and if after a few minutes of going in and out his cries had become hysterical, then of course I would have binned the CC and picked him up and cuddled him etc. But he seems perfectly happy and enjoyed his afternoon far more yesterday because he wasn't overtired.