Members of the Church of Zion claimed there was a medical conspiracy against the use of the chemical recommended by their church elders.
'Almost everyone sitting in the hall has raised his hand in support of what we are doing. I believe my church is great and is doing miracles to help us,' a beaming believer who would only give her name as Ms Chan said as she left the meeting.
Ms Chan said she had used the drug to wash her face and clear her complexion and it had had a good effect on her.
'The church told us that the drug has healed several thousand believers,' she said.
Tapes and videos were given to the users instructing them how to use the drug, which costs $30.
'It is so cheap,' she said. 'Obviously, the church is not stealing money from our pockets.' Ms Chan said doctors who said the drug could endanger health were making false accusations against God.
'I know that many doctors have used hydrogen peroxide to cure diseases, but they are just denying it,' Ms Chan said.
She said church elders had carried out a 'secret investigation' which proved the benefits of the chemical mixture.
She would not give details of what they had found.