He first came across the world of competitive tickling when his friend sent him a link.
Mr Farrier worked with cinematographer Dominic Fryer, and said he was "what makes this documentary look so pretty".
"He's a real talent."
Along the way, Mr Farrier was strapped into a chair and tickled by a professional tickler in Florida.
"It was for 10 minutes non-stop and it was just awful.
"It was like a full body workout. I ached for days afterwards.
"I found out my feet are the most ticklish.
"That scene didn't make it in the film, because in fact this film doesn't end up being about tickling.
"It turns into something else. A bit of a thriller, almost. Really, it does!"
He said it had been about four years since he had visited his hometown, but he was excited to return.
"I went to high school in Bethlehem. I worked for a year at the bank when I left school to save for university.
"I had so many good summers at the Mount, I can't wait.
"Tauranga is as good as New Zealand gets, it really is," Mr Farrier said.
"There's lots of talent in the Bay."
His family has recently moved from Tauranga further north, and have already seen Mr Farrier's film.
"It took two years to make this documentary, and I just showed it to them for the first time recently. They were surprised, I think, about what I'd made!"
After the Tickled Q&A tour, he plans to take it overseas.
"Tickled opens in America - HBO and Magnolia picked it up in June, so I am going to go to New York to show it there, and in LA," Mr Farrier said.
He is taking a break from his job at TV3, and will be working on other ideas for documentaries and his journalism.
Mr Farrier and co-director Dylan Reeve will be at the Rialto on Monday night to answer questions after the screening.
"I think, so far, audiences have had so many questions after the credits have rolled, and we want to be there to answer them!"