usually goes along the lines of having given their allegiance to Christ’s Kingdom and being neutral to human affairs.
They post their forms back to the Electoral Commission and no more is heard.
Yes that is what I and my wife did for many years as there are legitimate excuses that can be given and one is objection on religious grounds.
I also believe that some would go to a polling booth on voting day write on the form some scripture and place that in the box.
That way the Govt. wouldn`t know they were a religious nut.