Josh said in the future they would have to pitch to high-level Fonterra personnel.
"That will be quite scary, especially since they're a huge corporation."
The team said finances, marketing and sales, and constructing a business proposition were aspects the mentors would be giving advice on.
The mentors spent a few minutes with each team, sharing their experience and discussing the students' ideas.
Rotorua Youth Centre youth co-ordinator Alan Solomon was a mentor and said advice he would be giving included making sure the students did their homework with regards to the product they wanted to launch.
"There's no point advertising a product if there is no market for it."
He said he would also be advising them to trust their leader and the team, and to be prepared to work hard.
Director of technology for Ngati Whakaue and Apple consultant Adam Ellis was also a mentor.
Mr Ellis said he would be giving advice from a technological perspective.
It would "absolutely" be a rewarding experience to mentor the teams, as it was also part of what he did with Ngati Whakaue, he said.
Other schools taking part include Western Heights High School, Taupo-nui-a-Tia College and Tokoroa High School.
The scheme uses teachers and members of the business community to provide an authentic business experience for the participating students, who form companies, and launch and sell products.
The students learn how to adapt and collaborate, and gain a wide range of skills.