This is assuming that the subconscious is an actual cohesive whole. Things that are unconscious are just out of the realm of the conscious mind. Nowhere in psychology is the unconscious referred to as something that can actually "think". I think saying something like an affirmation over and over again just embeds that specific thought into our personality and nature. Our personality then translates over into the dream world. If the unconscious is intelligent then it would have to be able to understand and process information and make judgments based on the info. In other words it would have to think. If it can think then it is loosely an actual separate entity from ourselves. No where is there any evidence that this would be the case. In my opinion to many people think of the unconscious as this imaginary friend that is inside our minds reviewing everything we do. The unconscious is just that, that which isn't conscious. Any process that our brain has control of but not that we are aware of. Our heart beats and we breath because it is underlying programing in our brain structure, not because the unconscious is willfully making a decision to keep us alive.