Try this - when installing the clamp to the post, let the top of the clamp sit flush with battery post top, which leaves a gap between the bottom of the clamp and top of battery.
I notice the pass side battery clamp has a gap at its bottom, and very clean, yet the driver side battery clamp was resting on top of the battery, and it was full of that green junk. I removed the clamp, cleared off good, reinstalled it, flush to top of battery post.
And I sprayed a lube/corrosion control fluid on it. Seems to be working ok.
Going to try that as well. Noticed the green junk build up on battery clamp as well.