GW is definitely a gentler approach. Just a few notes on wiwo though, first of all you can expect a lot of crying when using that method as toddlers generally don't like whatever you are trying to change. Secondly, when you do use wiwo there is no designated waiting time to return, i.e. 5 or 10mins. If your LO is crying desperately like they need you, then you would return right away to comfort. It is important to know the different cries though, and what is a settling cry vs. an "I need you now" cry, kwim? It is a very useful tool, when the time is right.
My memory is fuzzy, but we did use more of a GW approach when DS1 was teething his canines at about 15mos, as he was just beside himself and wiwo was not working (generally though it has always worked very well with him). I was pregnant at the time too, although only about 5mos or so. I actually spent probably a good week sleeping on a mattress on his floor (it was THAT bad
). Then once I removed the mattress I would sit in a chair in his room until he went to sleep. At first it had to be a full 20mins until he was asleep, but gradually I moved closer and closer to the door, and then eventually was able to stand outside the door and soothe him with my voice.
The main point is that you want to secure trust with your LO, trust that you will be there when he needs you. Once he starts to feel secure, you can start spending less time in there.
I can't remember how long the whole process took me exactly. I know that things went bad in early December, and were fine again by mid January, so probably about 5/6wks in total but it wasn't horrible for that entire time. That was the just span it took for canines to come through and then for sleep to settle down again.
We had another regression about 18/19mos (before DS2 was born) and I had to start staying in his room again, but it took less time that time around, probably because I had done it before, but also he wasn't teething that time, it was just some random SA likely due to developmental issues or sensing the baby was coming so things were about to change.
In my experience though, since DS1 has always been a good sleeper and good habits are established, he always goes back to them even after rough times. You said your LO was a good sleeper before, so I've no doubt he will be again.
Sorry for the long winded reply.
