Peter cannot prove it, but said his father's friend took the recipe and started a popular chocolate company.
"I would regularly go home and he would make it, which proved to me he did have the recipe," he said.
But Peter said the true magic of the show will come from the child leads.
"There's a saying: never work with children or animals. With regards to this show I would say the children have been an example and just fantastic to work with," he said.
Mrs Salt, whose husband uses his riches to ensure their daughter receives a ticket by buying every bar of chocolate in town, will be played by Gabrielle De Bruijn.
She became involved after two of her children were cast as oompa loompas.
"It turns out most of the adults have their children in it, so it's a real family affair," she said.
Veruca Salt, the spoilt daughter, is played by Bridie Case-Miller, who said it was a whole new experience to play a brat.
"I'm the oldest child so I don't get much of that," she said.
Meanwhile Molly Huggan, who plays Violet Beauregarde, has had to learn to blow bubbles after a lifetime of not being allowed gum.
A highly technical show with a hot chocolate river, a girl who turns herself into a giant blueberry and a man who shrinks himself, the actors were unwilling to divulge the clever devices they will be adopting to maintain the illusions.
"We've got a glass elevator that's shown in the show. We incorporate modern technology, and when it's all put together it transforms the stage," Peter said.
The play runs from April 9-23, with matinee and evening performances. Tickets from www.iticket.co.nz