I remember the question from Ask. I had to do a bit of a search to remember the interpretation.
Crackers was obvious and still in use. It's just crazy. A Rozzer, as anybody who watches BBC TV will know is a Peeler. That just left dropsy and snide to look up and they don't apply in the land down under.
Our Rozzers want their dropsy electronically. If you bribe a cop in Oz you hand him your credit card which, if valid, will never be snide; Of course, if the rate of dropsy is too high, it might easily max out. And that would be crackers, indeed.