"I can't say I ever saw him do anything," a former director of a Kenja centre told the Herald after the screening of a documentary about Dyers at the Dendy Cinema in Newtown on Thursday night.

"I didn't have any intimate knowledge of what was happening in the rooms but what they wanted us to do was to all say that the processing doors were open because that was their argument - that Ken wasn't in the rooms on his own with the children - but he was."

Dyers's widow and Kenja co-founder, Jan Hamilton, said Dyers was cleared of those charges in court and last night she presented a "public lecture" entitled "Guilty until Proven Innocent: Jan Dyers and friends expose the facts about the attack on Ken Dyers, Kenja and your personal freedom".

The $65 "lecture" is actually a play reading, which would make little sense if you were not well versed on the allegations against Dyers.

Ms Hamilton also said the film Beyond Our Ken was "a tabloid beat-up with serious omissions and that she and Dyers were not given the right of reply.

But the film culminates in a scene in which Dyers responds to a question by poring over a young girl's body, explaining he needs to clear her of negative sexual energy. He then launches into a seven-minute tirade in which he accuses his persecutors of tactics used by Hitler, Mussolini, the Spanish Inquisition and the Salem witch hunt.

"I think it's a very balanced film," film-maker Luke Walker said. "I made sure Kenja always had their right of reply often to the detriment of the narrative."

The film-makers interviewed Hamilton, psychologists and cult-busting Uniting Church minster David Millikan as well as happy and disgruntled Kenja participants including Cornelia Rau, who was diagnosed with schizophrenia after attending Kenja sessions and ended up in an immigration detention centre.

They also interviewed relatives of another four Kenja attendees who either committed suicide or went missing, presumed dead.

The film-makers set out to demonstrate how one ends up trapped in such an organisation, which has been labelled a cult.

Kenja's basic tenant is that a human is a spirit whose potential is blocked by "negative spirits" that have "attached" themselves to the person's spirit in this and past lives.

In the film Dyers demonstrates how he rids participants of these spirits through "energy conversion" - a process in which he or a Kenja "processor" stairs at the subject for an inordinate amount of time.

The film says Kenja creates a non-threatening environment to teach their philosophy then isolates the participant from the outside world by filling their lives with expensive Kenja activities, leaving them with little time for sleep or engaging with the world outside Kenja.

Kenja runs many activities so participants can reach their potential but if the standard of singing and dancing shown in the film is any indication they have a long way to go or Dyers' philosophy was seriously flawed.

Mr Walker spent six months attending the Melbourne centre before Melissa Maclean came in with the cameras.

"I just hung out with them for six months and couldn't see the problem. They believed in peculiar things but many people believe in peculiar things. What's the problem with that? If anything I found it tedious and exhausting feigning enthusiasm for all that time."

But former participants say Kenja makes it difficult for you to leave the organisation, by suggesting people outside the organisation will not understand you, that you can't survive in the outside world without Kenja's support and if you do leave you will lose any contact with your only social network - Kenja participants.

"The problem with Kenja is they practise a form of unregulated psychotherapy; that's what energy conversion is," Mr Walker said. "The majority find it harmless but when someone has a latent medical illness such as Richard Leape [who went missing 14 years ago] and Cornelia Rau, it exacerbates their condition. When they start jabbering like idiots, they panic and throw them out. They don't want anything to show that Kenja doesn't work."

The film alleges Kenja sessions involved nudity and sex.

Dyers was charged in 1995 with 11 counts of sexual assault against four girls from two former Kenja families. He was acquitted of all charges.

In 2005 he was charged with another 22 counts of sexual assault against two girls who were 12 at the time.

Dyers twice asked to be declared medically unfit so he would not have to stand trial and was given a year's stay of proceedings.

The day Dyers committed suicide police telephoned him about more allegations of sexual assault.

The day after the complainant's father, a long-time Kenja participant, said he raised the issue with Kenja executives, one of them, Windy Tinkler, accused him of assaulting her and took out an interim apprehended violence order against him.

The father was charged with assault but this month was found not guilty and the AVO was revoked.

The film catches him before his daughter made the allegations, saying Kenja training "made me more effective in what I do in my business life and my personal life".

After the film screened on Thursday night he said he was left with a feeling of "betrayal" by Kenja.

Beyond Our Ken will screen in Brisbane on Tuesday and Canberra on Wednesday. It will also be screened in Melbourne on September 10 to coincide with its release on DVD.