The astral plane is important to be explored because it assists humans in understanding where they go when they die. However, the astral plane can be a scary place, just like when you land in a violent or criminal location you fear for your life.
Dead humans who have led a clean, benevolent life just pass through and make it to a high level in the mental plane. However, those who do remain in the astral plane for a long time, sometimes become demonic. And that is one of the reasons why the astral plane should not be explored often with the etheric/astral body.
For the time being, we believe there is no need to work in the astral plane.
Outside of learning the basics of the plane and understanding the many pitfalls that can occur there, the astral plane has little to give when it comes to solving the current leakage problem.
If you want to help humanity, it is better to work on the physical plane right now. It is better to work on methods of counteracting the astral, blocking the astral, stopping the leakage, ridding humans of pests, killing the pests that currently roam the physical land. Attempting to fight those much beyond your level of power and knowledge is extremely dangerous, especially if you have not been properly trained like those with a family lineage of fighting astral entities. Remember that who you pursue, may end up pursuing you, in other words, you as the predator may become the prey.
As for cleansing the astral, one would have to be in the astral. One would have to clean, redress and reform the demonic entities there. These entities or demonic dead humans have no intention of redressing themselves yet. It takes a long time for them to even succeed at altering their thinking process and their behavior.
Cleansing the astral is almost impossible at this time. It would be easier to figure out a way to block the thinning of the veil that has happened.