We know little about other dimensional mass consciousness of humans, but we know quite a lot about collective human behavior through our life experience and history.
I learned an interesting bit of information about mass consciousness of the Greys from a channeled message.
I don't know how true the message was, but its lesson was remarkable. The story goes that certain high level aliens were unhappy about how the Grey's hybridization program develops on Earth. There was much unnecessary suffering of humans, rudeness on the side of the Greys and lack of cooperation on both sides. The high level aliens were trying to convey the need for the Greys to comprehend human emotions and to learn human culture in order to avoid suffering and improve cooperation. (This is also one of main points of this book). As this message was conveyed to individual Greys, it was inefficient; the message was drowned in mass consciousness of Greys without any effect. Then the high level aliens figured out that to get the message across, they need to speak to large groups of Greys. So they started assembling large groups of Greys and speak to many at once. This had an effect and the Greys took appropriate measures to fix the problem - they created human-grey hybrids which were capable of understanding human emotions and this way they learned to comprehend humans much better.
So here is an opportunity to apply this lesson to human mass consciousness. You need to figure out a method to convey your message to humans without producing a mass panic. You tried doing this via individual humans and failed. What you need to do now is to convey your message to humans en masse, to large number of humans in limited time. This can be done through fantasy world and art: via songs, computer games, animations and movies. YouTube and other mass media can be used.
Consider seriously animations (animated movies). With your technology, talent and help of human artists you can produce many excellent fantasy animations which would compete commercially on human markets and will convey your message to large audiences. This is an easy back door to human collective consciousness.
The word animations is a bit ambiguous. I use it in a sense as animated cartoons. Disney animation movies are an example of the genre I mean. Avatar is a very popular animation movie about good aliens. It has a lot of violence, but for commercial success violence is not absolutely necessary. There are popular animations with minimal violence. "Strawberry shortcake movie" is popular and minimally violent. Animations are watched mostly by children, but adults are exposed to them too while children are watching. Adults usually oversee the children and are located in proximity. I believe entering the human collective consciousness via masses of children would be a great idea. Check out Wall-E animation movie. It has many qualities of the animations I recommend you should make: it is visionary, positive, exposes current problems and trends, shows positive solutions and it is less violent than many other children animated movies.