My therapy was in group format only. We met once a week, had social time, had a "confession time" for anyone who needed to get anything off their chest, and as a group we would read and discuss a passage from a book.
This group was pretty low-key and I don't think there was really any attempt to brainwash. However, given the lack of a scientific basis for the material, I often had some healthy skepticism of the effectiveness of it. One of the books we read had some very specific stories of people who had changed, but the author had only been in contact with them once, and there was no followup. So, yeah...
Yes, religious, and not sure if religion and homosexuality can coexist. Some religions, yes. My current denomination is affirming, but there's always a little piece of me that is more conservative about it and it nags sometimes. It's a bit like mixing oil and water sometimes.
Despite not believing in its necessity or efficacy, I usually am one of the first to defend groups like the one I went to (but not other experiences I haven't had, like one-on-one conversion therapy). Unlike stereotypes of the groups that have been shown in sitcoms as "meat markets", my experience was that a lot of the men were lonely and trapped between two worlds; some of them had children that they weren't able to see as much as they wanted to due to divorce. Etc. I got the feeling that those couple of hours were the only times some of the men got to smile during the week. There was a cameraderie that existed in that room and only in that room, where they were finally with other people who understood who they were as a whole person, which is not something that a Christian who "struggles" with homosexuality is usually able to find. The vibe was not sexual at all.