Bad smell in blackpropaganda

At the beginning of the week, as I got something from the fridge a rather unstable milk jug discharged its contents all over the lower shelves meaning milk was everywhere. SW.. took control, wiping everything, and also the inside of the fridge. Hope fully all was well, and then by Wednesday there was this smell - that sweet smell of dried vomit - and we looked a round for what could be causing it.
Then I though about the milk - and so today the fridge was emptied, washed down thoroughly with bi carb of soda , and the floor swabbed with bicarb and bleach.
We just hope that sour milk was the cause.
Of course, I can still smell something - but is that me imagining the smell?