Scatter-gather idea with helm

Question

I love that I can quickly capture ideas with org-capture. For my academic writing, these get sent to a scientific_journal.org file. After a while though, I find that I have many related post, scattered throughout, which need to get grouped under a common heading or sent off into a separate document.

What I would like to do is search my capture document with helm and mark all the relevant candidates, then [TAB] to a helm action that lets me batch refile these at once.

I found some discussion of this earlier here and here. And John Kitchin has some code to get this done outside of helm:

http://lists.gnu.org/archive/html/emacs-orgmode/2017-04/msg00056.html

and he also posted some code to bulk-apply actions in helm:

http://kitchingroup.cheme.cmu.edu/blog/2015/01/24/Anatomy-of-a-helm-source/

But, as someone who is relatively new to helm, I'm having trouble piecing the two bits together...

Any ideas?

Thanks!