What is so scary about contacting your own subconscious? I say we should let the truth about the mind be revealed, you will not be deceived by demons if you practice self-inquiry and self-hypnosis, both are proper tools in the life of the seeker but religions will normally work to supress the truth about personal power.
The danger is this. We have trouble finding truth with people. How are we going to determine truth if we contact spirits?
The inner mind has always held ways to contact spirits. The complexity of mind is one of the things that keeps spirits out.
When we open up the parts of the inner to direct contact from our outer mind, we open up contact with the spirits.We have very little control of inner mind. The spirits are often deceptive, teaching things outside of the realms of things that we can control easily. They can open us up to false things as well as true things, but we won't know the difference.
In addition, the complexity of the mind is so great that we don't easily understand what we are looking at when our inner mind feeds us some of its own data.
Stay away from contacting your inner self if you want to stay away from opening up a path for spirits to feed you their information. You won't be able to distinguish the truth from falsehood. Many people that have done this, have gone insane, or else lost control of their own thinking and belief system.

There are no spirits. That is the reality.
When you talk to God, you are religious.
When God talks back to you, you are insane.