They said during a Manhattan news conference that they were subjected to humiliations that included stripping naked and taking a baseball bat to effigies of their mothers.
The four attended sessions at the Jersey City, N.J.-based Jews Offering New Alternatives to Healing, or JONAH. The nonprofit advertises in Jewish publications and claims to rid men of same-sex attractions.
Three of the men at the news conference are Jewish, and the fourth is a Mormon now living in Salt Lake City who was a college student in New York when he signed up for the services.
The four say the methods do not work and should not be marketed under New Jersey's consumer protection laws.
JONAH did not return calls requesting comment.
The group's mission statement on its website says JONAH is "dedicated to educating the world-wide Jewish community about the social, cultural and emotional factors which lead to same-sex attractions."
Its claim that being gay is a mental disorder that can be reversed has been rejected by the American Psychiatric Association.
Speaking for the men at Tuesday's news conference were attorneys from the Southern Poverty Law Center, a Montgomery, Ala.-based civil rights organization.
"JONAH profits off of shameful and dangerous attempts to fix something that isn't broken," said Christine P. Sun, the center's deputy legal director. "Despite the consensus of mainstream professional organizations that conversion therapy doesn't work, this racket continues to scam vulnerable gay men and lesbians out of thousands of dollars and inflicts significant harm on them."
California has taken action against providers of conversion therapy.
Last month, California Gov. Jerry Brown signed a bill that prohibits licensed mental health professionals from using so-called reparative or conversion therapies with clients under age 18. Brown called the therapies "quackery" that "have no basis in science or medicine."
Two New Jersey lawmakers are drafting similar legislation.
(Copyright 2012 by The Associated Press. All Rights Reserved.)