Any time I remember a dream I've manipulated it and I never dream in 1st person.
The subconscious is mostly comprised of your body functions that occur without you thinking about them. There is more to it, it has cognitive abilities but ultimately its nowhere near as big a deal as pop culture and self help books make it out to be. Its not even part of psychology, even Freud dismissed it as being a good term or important.
Your cognitive mind is more responsible for your dreams. Hypnosis is also based in the waking cognitive and rely on you being open to it and is nothing like its portrayed in magic acts and tv, its basically the placebo effect. Subliminal messaging is theoretical. We don't know it work and it to is sent to your waking mind, just a ton of times without you knowing to try and make you think or do what is being represented for the most part science feels its just another example of the placebo effect.