Yes conversion therapy never fully went away although some states have banned it and others have banned the use of shock as aversive despite allowing conversion therapy to continue

To clarify: there are several things people refer to as shock therapy

Ect or electro convulsive therapy is sometimes called shock therapy. This is not conversion therapy. This is evidence based for treatment resistant depression and bipolar disorder. This has an ugly history but the modern version can be very helpful if you’ve had years of no success with treatment. That said this should be something that you discuss and consent to

Conversion therapy is a form of Aversive conditioning. Shock therapy in this context is using electricity as the aversive stimulus. This is a behavioral conditioning technique to pair stimuli. It is theoretically simple and essentially based on the work of Pavlov. I take a thing you like and consistently pair it with something aversive. Eventually you associate the thing with the aversive.

So I may show you gay pornography and give an electric shock. But any aversive can theoretically work: I could show you two screens: gay pornography on one and gory death shit on the other. I could get one of those air horns and blast it to surprise you. Etc. modern conversion therapy goes way harder than this, they’ll do weird fucking shit like put a pressure sensing ring on your cock and show you hot guys, then introduce the aversive when you tingle.

Do you see the issue here? They believe they are making gay pornography aversive to you. But what’s really happening is that they are making expression of sexuality aversive. In the weenie monitor example it becomes getting an erection. This is because the people doing this are not only monsters, they are shitty at their job. They do not understand (or more likely willfully misunderstand) basic risks of what they are implementing and they also do not plan for basic realities like generalization (eg if I make homosexual erotic content aversive to you what’s to stop you generalizing that disgust to all erotic content? That’s a risk they’re willing to take, apparently, and a part of informed consent I bet money they do not explain (amongst many many other things))

Conversion therapy is torture. Aversive conditioning in general is. Anyone who does it should be in prison. They are monsters who care more about their agenda than their clients well being (which they likely do not care about at all)