Hypnotized Marionette ~Conclusion~

I know, but hentai (and media in general) hypnosis has nothing to do with the real one. Actually you can't use hypnosis on just anyone, there are different categories of people in regards to how easy they go into trance. And it's not just a flashing mobile telephone or finger flicking and the person is instantly your puppet. And most importantly: it's not as easy as you will forget everything you did once the hypnosis ends. Like you hinted, you suggest people what to do while they are in trance and depending on their character they will do it. Why should they forget everything afterwards? It's like you would say that everyone who drinks alcohol and does stupid thinks while drunk will forget everything once he/she sobers up. Some people do, but most not. While it's true that some people use hypnosis to forget certain memories (and I'm not quite sure if this will actually work), they actively want to forget and don't get lured into it so that somebody can cover up the crimes he/she did with hypnotized you.
But of course hentai hypnosis is nothing like the real life one. It's like with anal to vag or alcohol into butt pouring: in hentai they do it all the time, because it's an element of the story telling, but in real life it's not the smartest of ideas and won't work out like you've read in the stories...

Yeah, she did figure it out eventually and then fake it, but for most of the time, she wasn't faking it.