Hiya Sheldon, welcome to the forum!
I'm not sure about Oz, but I would assume that you can acquire a lot of the chemicals we have here, such as WilBond deglosser or Paso "liquid sandpaper"...Nothing works better to assure adhesion of a coat of paint like a good scuff with some 220 sandpaper, tho...
Those chemical agents are available here in our hardware and paint stores...That'd be a long drive for you, I'm afraid...
Good luck