"Chateau collapseaux" is, as gnu said, a type of wine packaging which is a cardboard box containing a plastic bag with a sort of spigot-type dispenser attached. Called a wine cask and described as a bag in the box. The bag collapses as the wine is used up, keeping the wine in a vacuum and therefore keeping the air away from it and preventing it from going off too soon. It radically increased the domestic consumption of wine in Oz - positively influenced the wine industry's profits. (Invented by a South Oz man called George Malpas. How do I know that, and why do I still think Google is absolutely wonderful? Because as a reference librarian in the early 80's I spent months trying to find out who invented the wine cask - reading books, looking up encyclopedias, any possible info source I could think of. I finally found it. By that time the customer who wanted the answer was probably just a pile of dust somewhere. )

Since wines are often given fancy labels like Chateau de Whatever, that's where this apt description comes from.

Spunk (male emission) => spunky (a man who is good in bed) => a spunk (a sexy man.

"Fully sick" is the term for something or someone who is especially impressive - or something like that. It's possibly youthful contrariness, turning a negative word into something positive.

Esky is a brand name for the original portable cooler. It was metal, with an inner and outer layer, made on the same principle as a thermos flask. Put ice in it and you can keep your coldies (cans or bottles of beer) cold at a barbie or picnic or the footy.

Helen