So...controlled crying. Yes we have. At several points.
First time DS was around 6 months. I now feel hideous about it. He was clearly too little but...we did it to break a sleep habit. He used to fall asleep perfectly, either off the boob or self settling but would then wake after 40 mins, you could literally set your watch by him, and not settle for ages with hugs etc. IT worked for that.
We then did it again at 7-8 months after we night weaned. Worked very well, and very quickly (2nd night). DS still wasn't sleeping through but would only wake up once or twice and go back to sleep immediately.
At 10 months he slept through for about 6 weeks. Then a combination of teeth, colds etc f--ked it all up until, well last week really...
DS was waking up and driving us nuts with not going back to sleep, sounding upset but then laughing at us when we went in. After two weeks of shit sleep I told DH we had to man up - shut out door and his and left him to it, tied in to us being pretty sure teeth were over (he only has his final 4 molars left 
and that he wasn't poorly). We have to be a bit careful as DS has had some night terrors, but this are easy to tell. I would always go in to him once to work out if he is genuinely upset or if it is all a game.
Top tips....you and DH need to be on the same page. I was way tougher than DH. He'd have gone in in a heartbeat. I was like a woman possessed and practically pinned him down to stop him going in (sleep deprivation is not my friend).
It needs to wok for your LO and you need to be consistent. The second night we could tell it was working (i.e. he cried a whole lot less). It helps your resolve if you see it working, 'proves' you are doing it right etc.
On each occasion we have done it has taken 3 days, max. The most recent time it was one night.
We have a problem. DS throws things. Not in itself a problem (yet). But the arm action is as he does it at us is like hitting us - well, it is hitting us. Does it with his hands, books, remote controllers. He is 16 months which I think is too early to know right from wrong. I have been holding his shoulders, looking him in the eye and saying 'no!' but he wets himself laughing at me. It's infuriating (but I have to try so hard not to giggle). Today he pulled my hair (really hard - sounds so petty) and I smacked his hand 
. Hated myself. He cried. Doesn't help that at the moment he hates me and only wants DH. To the point where DH went to the supermarket today and DS stood crying at the door for 20 mins. Couldn't do anything with him (this was before the hair pulling)
So in short, well, long, I feel like the world's shittest mother whose son hates her