No as “walling” alone to these visa violating immigrants would not work in isolation.
Extraordinary rendition to extra judicial places outside Australia and using suitable methods of torture such as waterboarding, light deprivation, sleep deprivation, stress positions, ghost detention, mock isolation, and others could be to use to severely cut the number of potential immigrants to Auatralia.
Many extraordinary rendition methods should be used as immigration and the immigrants that are flowing into Australia present a clear and present danger to the ongoing viability of Australia as a nation state.
