Once I've composed the right Song, I can teach it to you - it's never entirely safe, but learning only one, with limited applications outside this specific situation, shouldn't pull you in too deep.

Aside from that...once we've cleared a doorway, it would be well worth our while to analyze the warped lattices corresponding to the alien Dreamers to see exactly what about them makes Questing Country respond like they're a hostile body. I have my theories, but once we know for certain, it might be something that can be addressed without extreme measures - either on our part or that of the local population.