They were selling their product at $10 per 150g, as well as wrist pouches to hold the treats while dog-walking.
The girls would continue to develop their business model as they worked towards the national finals at the end of the year.
They also received a special invitation to present their plan to the Hawke's Bay Business Hub.
Year 12 Hastings Boys' students Brian Towler, Callum Williams-Legg and Jade Bartle, of BCJ, came up with their Easy Strop idea after seeing the struggle of truck drivers on a day-to-day basis.
Callum said the tool itself was very simple but very efficient, and was used to wind up strops or tie-downs in a matter of seconds - doing so manually would take around a minute.
"The BCJ team was definitely surprised with the outcome of the competition, we were overall extremely thrilled when we found out that we had come first equal," Callum said.
"[We] are very pleased to know that we are the first ever HBHS team to have accomplished this massive milestone."
Head of commerce Kevin Atkinson said the team's product showed a lot of innovation. In the first year the school had taken part in the scheme, he said the calibre of all their 17 teams was high.
- To follow the Iona College girls' progress or to buy Ruff Tucker, visit ruff-tucker.mystorbie.com - or to find the boys of BCJ and their Easy Strop product, go to www.facebook.com/BCJLTD/?fref=ts