Hon, this will be brief as I'm in the crazy hours, lol.

We took DD1 twice for sleep issues - she was a rubbish day sleeper! I actually thought they were quite good TBH and I learnt some good tips. DD1 'beat' them both times though - we were sent home early both times cause they couldn't get her to sleep! They do comforted crying where you pat your baby in the cot and speak quietly and reassuringly to them. If they get really upset, you pick them up and settle them again (feed if necessary) then put them back down once settled but still awake. Their aim was to get DD1 out of the sling for naps - they did initially kinda blame her dependency on the sling for her day sleep issues. Well they ate their words literally when they told me to put her in it early arvo so the poor baby could get some sleep! DH and I laughed so hard!!

I did learn some good things though and I honestly believe it helped to finally get DD1 sleeping in her cot for day sleeps (magically!) at 6 months. I have never let my girls CIO, it's not for us either and just doesn't work. I think the Ngala approach is pretty good and watching your baby on the TV monitors is really interesting! Give it a go I say