This is frankly bloody unlikely.
I’m no expert on it, but I know for sure hypnotism isn’t like in the cartoons or movies, and holy shit it’s not like in recent episodes of Gotham (don’t get me started). It only works if you want to be hypnotised, they can’t just pull out a pocketwatch and the ticking suddenly turn you into a psychotic vegetable.
No, because it’s IMPOSSIBLE.
You CANNOT get hypnotised against your will. Full stop.
That is NOT the same as saying you can’t be made to do things against your will once hypnotised. I’d say that a very skilled hypnotist can make you do quite a lot of things, mostly by tricking your mind rather than direct instructions. e.g. you can’t be told to kill someone but you could be convinced the gun they give you is a toy gun and so shoot it at someone.
Can you maybe get triggers put in that you don’t know about once you are in a hypnotic state, that make you act strangely? Yes, it seems likely if you’re very susceptible to hypnotism, I reckon that’s possible too – which is why you should only ever try it with someone you trust.
Now when it IS something you want to do anyway, well then it gets very, very effective in my experience. To the point where you don’t really need to be hypnotised in any classic sense, you just need to keep being edged, keep being told you can’t cum without permission, and then, suddenly you find you can’t!
BUT ONLY IF YOU WANTED THAT IN THE FIRST PLACE.
But again, I’m not an expert, if people want to correct me, feel free. I’d be interested to hear about it.
So, my advice as to how to cum?