Hi, I've got a couple for you.
"Thick as two bricks"
"A sandwich short of a picnic"
"As useful as a pocket on a singlet"
"As useful as teats on a bull"
Responding to 'how do you feel' - "Like three penneth of Gawd help us"
I could go on and on, as I had an Uncle who spoke mainly in ozzie slang, and we just had to try and keep up.
Eddo