Aussie version of "Holy Moly" or variants. Slightly archaic/rural (read: Westie/Bogan etc), but still sometimes used by kids in front of Authorities. Also spelt "hoolEy doolEy"
An act of redemption by electrocuting oneself , i.e. After being raided by the Police for child exploitation images, Darren John Hollitt, paedophile, hard-wired himself to the mains power and removed himself from the gene pool.
"What happened to that 'Darren'?"; "Oh he did the Holy Hollitt!"