Remove interior faces for 3d print prep

This is going to be a tabletop miniature. I love the art style the sculptor did, but unfortunately the topology is very sloppy for something intended to be printed. All the pieces of the character came in separate parts, so I separated by loose parts, and fixing manifold issues as I boolean them together one at a time.
I ran into issues with the hands.
The fingers are curled and have some intersecting faces. Because of this, Boolean unions, like trying to add his axe, aren’t removing the interior faces.


Is there a way to clean up this topology without doing it manually?

normas troubleshoot.blend (3.5 MB)