I rang Cow&Gate and asked them what was in this milk which made it different.
It has rice flakes and potato starch in it, which thickens it and makes it sit in the stomach 'a bit like you having a large pasta dish before bed time' . It's not for babies under 6 mths, and it's not for more than one feed because otherwise it would be 'too heavy' for the baby.
No, it doesn't guarentee a baby will not wake, but 'as part of a bed time routine it may help settle a baby' (they clearly have a consistent script!).
This is a marketing exercise for Cow&Gate, that's for sure, and watch out for other manufacturers bringing out something else that's similar in intent.
'Soother Milk'
'Snoozy Milk'
'Sleepy time Milk'.
They sure as hell won't call it 'Potato and Rice Gloop'.
(all the best to you, babyjj - you've led us down some interesting byways!!)