Selling a car without RWC what are my obligations?

[the evil twin]

After a bit of googling, the recommended process is to keep one plate and let the buyer know of the timelines (say 10 days) to produce a RWC for registration transfer, if not then I can go to VicRoads with the other number plate and cancel the rego.

Is one plate enough to cancel the rego?

Cheers,

Why would you want to do that... that is a HUGE risk to you and none to him
Just do it the way Cuppa and Vic Roads suggest, hand in the plates and sell it unregistered.
Selling on the presumption that he will get RWC, complete the transfer etc is fraught with danger.
The car is still registered to you if something goes pear shaped