Solid Difference Two Lists

Hi Guys,

I've got an issue that I've seen posted a few times but couldn't seem to find a solution for, so I figured I'd start a new post for it and see if we can't have it out.

I've got two sets of solids that I'd like to perform a solid difference on, subtracting one set from the entirety of another. I can't seem to set it up that so that it performs the operation on the same object. It always seems to boolean one object, then copy the solid and then boolean again with that new object, resulting with many copies of the original solid, each with it's own cut, instead of one object that's been cut many times.

GH definition should be attached, and here's a look at the way I've got it strung together. Any help would be appreciated. Thanks!

-Clayton