Hi Grea,
the treatments you have read about, daily cialis, to help with recovery of erectile function are not relevant if your OH has had all nerves removed. Without nerves he will not be able to get a spontaneous erection so event tablets like Cialis, Viagra and Levitra will not work either.
In England, men that have had the op are entitled to a proper vacuum pump on the NHS (not to be confused with the cheap ones available from sex shops) but I understand that in Australia these are very difficult to come by and can be very expensive. The vacuum pump has two functions - used daily to maintain the size and health of the penile tissue or used with constriction rings to have penetrative sex.
For men with no nerves, or for whom Viagra etc doesn't work for other reasons, there are two other options - an injection called Caverject or pellet called Muse. He could talk to the GP about pumps for the time being and then injections & pellets when he sees the surgeon. In the meantime, as soon as possible it would be good if he learns how to have an orgasm without an erection - this is possible with oral sex (if he isn't too leaky) or by masturbation and made easier if he (or you) use lots of lube.