IMO yes they'd be successful.

Full disclosure, my experience with hypno is more kink related and not in a medical context, so my experience will be drastically different than those that get into hypno for therapy because most of the time the people performing it in my case are amateurs leaning heavily on preexisting dom/sub power dynamics (ie not "true" hypnosis). YMMV.

I don't really visualize things in my head at all. Sometimes on a good day I can imagine almost a fuzzy smoke like outline, but this isn't a typical day for me. I can imagine sounds, smells, tastes and especially touch/sensations.. ickplant@lemmy.world made a great point in one of the comments here. Using the word "pretend" is a far better delivery.

In my personal sessions I have the best experience when people can suspend my disbelief and make me believe they are incredibly skilled, even if maybe they aren't. Part of that is just me really wanting to be hypnotized, and honestly that's the biggest thing. If you want hypnotized you will be hypnotized, and if you don't, you won't.

I can pretty much just think about the sensation I feel during hypnosis and put myself into a sort of pseudo trance at this point. I listen to audios occasionally and try and do a session with someone about once every couple months. I'm not really fully educated on the mechanics of it all, but I know I enjoy it.