With Benson also winning the open men's fly final the nine-strong Sundevils contingent returned home with two titles and one podium finish.
"I spent a couple of nights celebrating with family and then got into serious training again with this weekend in mind," Greening said.
He was referring to the Greendale club's meet at Flaxmere Waterworld this weekend. Greening is one of 67 Sundevils among more than 160 entries.
"I'm going to have a crack at the Hawke's Bay-Poverty Bay record of 23.29s ... I'm almost there," the 2m tall Greening said.
Former Sundevil Matt Thomas set the record during the 2004-05 summer.
Benson has no doubt Hastings Boys' High School product and former Wakely Shield rugby player Greening has the goods to achieve his 2018 goal.
"We just need to put a bit more meat on his bones and he will get there. Most top swimmers peak in their early 20s these days."
Between pool and gym training sessions, Greening does eight of each a week, he can train up to 30 hours each week.
"It's my No 1 sport and that's the level of commitment I need to put in to achieve my goal," Greening said.
He is also ranked among the top 10 in his age group for the 50m and 100m backstroke.
Macky, in fly and freestyle sprint events, and Matt Sexton in 100m and 200m breaststroke events are other Sundevils tipped to shine at the meet which has events tomorrow afternoon and Sunday morning.
Ella Jamieson and Bevan Jacobs will spearhead the Central Hawke's Bay club's assault. Mahina Ross and Sam Whiteside are among the Aquahawks expected to perform well and Olivia Gray will be among the host club's best hopes.