Lynne is in the bath. She thinks to herself that cousin Norm is visiting from Australia. She continues to think that he is a lifeguard and likes to keep his hand in. Norm bursts into the bathroom and Lynne shouts 'Bondi Beach or no Bondi Beach'.
The water shortage has hit Wimbledon hard. Lynne's baths are now a centimetre of water and an awful lot of Fairy liquid. She cleans herself in the shower but has refused to give up that relaxing bath time she enjoys so much. So instead she creates the atmosphere of a relaxing bath, but without the water.
Cousin Norm is a bit strange. Oz probably doesn't mean Australia in this case but the Osmand Mental Health Hospital, known as Oz. Norm is actually George's cousin and has been locked up for quite a while. In order to attempt to reintroduce him to society, George has agreed to let him live at their house for a trial period of a week. He has delusions of being a lifeguard, a side effect of his Hero Syndrome, which got him locked up in the first place.
To not draw attention to Norm on this experiment, George and Lynne have devised a code word if Norm does anything untoward. It is a bit long winded but it is decided that the code word will be 'Bondi Beach or no Bondi Beach'. George hurried into the bathroom seconds later to find Norm attempting to drown Lynne so he can save her. Needless to say, Norm was returned to Oz that very afternoon.