dry as a nuns nasty
Very dry. A nuns vagina should be dry (supposedly) and therefore to say this means its very dry.
"Hasn't rained in months, its as dry as a nuns nasty"
dry as a nun's nasty
beer-less place. Aussie-speak.
Well, mate..get off yer sedentary butt and go get us some Foster's! This place is dry as a nun's nasty!