There success rate has been terrible. Christian run conversion therapy programs started really taking off in the late 1980's and reached their peak in the late 1990's. Of course the programs just gave glowing reviews of their own programs. Then in the early 2000's the medical field started showing statistics that such approaches don't work and do great harm and were advising people to stop them. Then around 2005 it started coming out that the religious programs were not successful at all, and had horrible results, but of course the religious didn't listen, but it all fell apart anyway. One by one the Christian programs disappeared as they realized the errors of their ways. The last large religious mainstream like program eventually left was "Exodus International". However, three years ago they finally admitted such programs don't work, made an apology for the damage they had done, and shut down, and Exodus International was the one that started it all back in the 1970's, and basically the last to shut down.
The heyday of many such religious programs are now gone, and only a few small splinter groups are left, struggling to stay afloat.