Constable Dermot Forde of the Henderson Neighbourhood Policing Team and Youth Aid Constable Reuben Jakich have teamed up to talk to teenagers at Alternative Education centres.
In their presentation they give an audience member a pie - then take it back, spray it with acetone and other nasty chemicals and offer it again to their volunteer.
"We say 'who's hungry now?'" Forde told police magazine Ten One.
Waitakere Area Manager Community and Youth Senior Sergeant Richard Thompson said Forde and Jakich had "broken the ice" with youngsters in advance of a planned long-term campaign on synthetics.
"What they have achieved is considerable," he said.
"The feedback has been genuinely positive and this group of kids are a tough crowd.
"They've created an opportunity to reach people who could be some of the most at-risk in a quick and efficient way, and to build on the conversations they've had."
Thompson applauded the non-traditional way the officers were appealing to young people.
"Giving staff the freedom to develop their own ways to achieve police's big-picture aims is an important part of what the Police High Performance Framework is about," he said.
Synthetic drugs have also been linked to an increased risk of seizures.
Effects include, but are not limited to: decreased motor co-ordination, fast or irregular heartbeat, disassociation, dizziness, paranoia, psychosis.
Use of synthetic drugs in New Zealand has also been linked to renal failure and heart failure.
(Source: alcoholdrughelp.org.nz)
Where to get help
If you, or someone you know, is using synthetic drugs, police urge you stop immediately and seek help if needed by contacting your local GP or by ringing the Alcohol and Drug Helpline on 0800 787 797 or text 8681 7 days a week to speak to a trained counsellor.
If you or someone else is in immediate danger call 111.