Origin: someone invented this phrase to describe the countless number of these people milling around (in tight cliques) the streets of Oxford.
Use: the word "versace" is used to describe a group of "sloanes". In this scenario "versace" takes on the same role as (and a similar meaning to) the word "phalanx".
The use of the word 'versace' is important as it adds a far more embellished description of those you are referring to. For example: sloanes are gaudy, cheap and of no substance. Similar to the flamboyant clothing produced by said designer that only looks good on a yacht/catwalk/celebrity.
I was walking down Cowley Road the other day and almost got run over having to walk around a versace of sloanes.
One of my friends is a sloane, she knows so many fit women. Man I was at a party the other night and it was one big versace of sloanes. Those girls, they may be stuck up but once you're on the inside, they are proper goers!
I was on the Divvy Road (Divinity Road, what they would refer to as their "hood" thinking they're ironically cool, we all call it a street) the other day and a versace of sloanes went past in a convoy of Golfs.
I tell you, if you want to see a versace of sloanes you should pop into Oxford during term time, they all go to "Brookes University" so that their parents can say that they go to "Oxford".