Well done on finding a solution! You must be delighted!

We found a very similar technique in a book called 'The Lull-a-Baby Sleep Plan' and it's worked so well for us this last month - even with teething we still only get 1 or 2 wakeups. The great thing is that it gets easier and easier, as they develop really positive associations with bedtime. It's easy to think that self-settling means crying to sleep, but it doesn't have to be this way - they can be soothed by your voice, and then when they're calm and happy, settle themselves down to a nice long sleep!