Corkery - alcohol-free for six years - said recovery from addiction was still close to her heart. "People came up to me in the street and told me about their family members who were dying from drink and drugs," Corkery told the Herald on Sunday.
"There was a more overwhelming reaction to my charity than there was to my dancing."
The money will be distributed according to the number of text votes each contestant received. Winner Barnett's charity, the Salvation Army, gets the most cash.
MediaWorks was not able to provide a breakdown of how much each charity would get.
Actor Ben Barrington nominated St John, Colin Mathura-Jeffree chose Alzheimers NZ, Jay-Jay Harvey went for Fertility NZ and boxer Shane Cameron backed the Child Cancer Foundation.
Siobhan Marshall nominated South Pacific Animal Welfare, Teuila Blakely chose Women's Refuge, surfing champ Maz Quinn opted for Surf Life Saving NZ and Chrystal Chenery chose the Home and Family Society of Christchurch.
Child Cancer Foundation chief executive Robyn Kiddle said it supported more than 500 families nationwide at any given time and money raised by fans of Cameron and his dance partner Nerida Cortese was welcome.
Lisa Honeybone from Surf Life Saving NZ said cash raised by Quinn would contribute to equipping the 4000 volunteer lifeguards on beaches this summer.
A spokeswoman for MediaWorks said the broadcaster was grateful to the public for the $70,000 contribution to worthy charities.