The city is stepping up efforts to shame prostitution customers — including the prospect of sending them off to "john school” to teach about the horror of ?human trafficking.

It’s all part of a police initiative to reduce the online sex trade in the city by 20 percent over the next year.

“(The johns) are fueling a violent, violent industry where young people get harmed, and many never come back from that,” said Lt. Donna Gavin, head of the police department’s Human Trafficking Unit. “It’s not OK to come into our community, exploit our young people and then go home in the suburbs where you think no one’s ever going to know.”

Police are set to receive a $30,000 grant from Demand Abolition, a Cambridge-based advocacy group, to bring city and state officials together with victims’ rights groups and other local organizations to go over new strategies to fight sex trafficking, Gavin said. The effort is part of the ongoing CEASE initiative.

Jake Wark, spokesman for Suffolk District Attorney ?Daniel F. Conley’s Office, said the state’s Human Trafficking Task Force and the DA have pushed for a “john school” — a required class for men charged with solicitation where they interact with victims of sex trafficking — as a way to make men aware of the criminal world they are supporting.

“If a first-time drunk driving offender can have an education program, I see no reason why we can’t set that up for solicitation as well,” Wark said.

Gavin said that program was one her group would push for, adding: “I definitely think that’s something we’re looking to do.”

She said the groups will still focus on providing resources to victims of the sex trade and go after pimps and traffickers, but they also want to target the buyers. She said people soliciting sex want to believe they’re engaging in a “victimless crime,” and refuse to think of the exploitation.

“They don’t think and don’t want to think this could be an underaged girl, doing it out of desperation, who doesn’t have a family to go back to,” Gavin said. “They may want to believe it’s a victimless crime, but when we confront them, they are ashamed.”

In the past, BPD has published names and photos of men arrested for solicitation and sent letters to people whose cars were seen idling in areas known for sex trafficking, Gavin said.

Suffolk University Professor Emeritus Kate Nace Day, who has made documentaries about sex trafficking, said shaming can be a powerful force to thwart demand.

“Many men do it because they can do it and the price is not very high,” Day said. “This is putting a price on it, a social, moral, personal price on it.”

Advocacy group plots plan to thwart solicitation

JOHN SCHOOL: A program where people charged with solicitation attend classes about sex trafficking, potentially meeting victims of the trade.

GOING PUBLIC: Publicizing names and photos of johns arrested.

DEAR JOHN LETTERS: Letters sent from a police department to the owner of a car seen loitering in areas known for sex trafficking, saying the car has been observed there.

CAR SEIZURE: Impounding a car used during solicitation.

REVERSE STINGS: Setting up decoy ads used by undercover officers to respond to johns in online forums.