Is there an exemption for an American gigolo held
captive by Australian women?

No.

My identical twin brother has been in OZ for three
years now on a 3 month visa. These women who take
turns using him are refusing to pay him other than
room and board and have told him he'll go to gaol
if he escapes. He wants me to come to Tailem Bend
to take his place so he can leave on my passport.

What would you do?