It's well documented and understood that hypnotism is complete bullshit, and only used as an excuse for clever trickery by magicians and the like. That's why there's been zero reported court cases of people being tricked into something hypnotized, except perhaps on TV dramas.
If someone REALLY wants to allow their character to fall under the influence of someone who's going to all the trouble, then let them. Otherwise, unless some serious drugs are involved, this is quite silly.
Without going in-depth, hypnosis relies on putting someone in a state between consciousness and sleep wherein the mind becomes very prone to suggestion. Hypnosis usually only works if the subject is a willing participant. This all said, RP is champion of all. If you want to RP hypnosis/brainwashing, find someone who's game to do so and RP it, but not everyone likes their character to be forcibly controlled. All this being said, if you want to manipulate people, just look up grifting techniques.
Yes, I have. And no, it doesn't. You are in fact no more 'susceptible to suggestion' when you're half asleep. That's the complete bullshit part. Hypnosis 'works' when the participants are willing and capable of responding. That precluded a 'half-asleep state'. There's literally nothing to it.
And if there really is an existing way for a player to "achieve coded puppety" over someone else's character, and it's IC, well I'll be damned, I've never even suspected such a thing.
The point is, coded state-of-hypnosis, meaning coded capacity to override someone else's will or perceptions, is totally meaningless because the victim's player absolutely has to consent to RPing the result of such a coded status.
A coded skill resulting in a coded status is totally useless if the other player doesn't play along.