I would like to do some stylized typography with horizontal lines inside the letterforms' shapes...this is a common effect.
I can't find one method that will work for me, other than divide, and that leaves me with a lot of hair-pulling tedious selecting all the unwanted bits and deleting them!
clipping paths won't help me, because I can't get it to clip the stuff inside!
I know this has got to be an easy thing to do, but I'm in the weeds over the procedure...anyone with a suggestion to get me on track with this?
ALWAYS state what version you are using.
horizontal lines inside the letterforms' shapes...this is a common effect.
As Larry mentioned, a Pattern Fill can be used. And can be applied to live text:
...divide...leaves me with a lot of hair-pulling tedious selecting all the unwanted bits and deleting them!
You're using Illustrator. Everything is tedious. AI is particularly weak when it comes to cutting open unfilled paths (as may or may not be contained in the Pattern Fill). If you need the effect to be completely deconstructed down to simple paths (for example, as needed to cut sign vinyl)--depending on what version you are using--the Shape Builder tool can be dragged around to delete outboard portions of the expanded artwork. But you can also use the Merge Pathfinder (described below).
...clipping paths won't help me, because I can't get it to clip the stuff inside!
I don't know what "can't get it to clip the stuff inside" means. If you want help, take the time to describe exactly what you are doing, using the commands and terminology of the program.
Understand: A Pattern Fill is really just a bunch of repeated elements contained in a clipping path. You can see this if you Expand a Pattern Fill; you will have a clipping path containing an array of duplicates of the paths you used in the Pattern:
You can then apply the Merge Pathfinder to trim down to the clipped portions. Merge unions contiguous same-colored fills, punches overlapping different-colored fills--and outlines strokes in the process because, like most everything in Illustrator, Pathfinders can't properly cut open unfilled paths, either. So after applying the Pattern Fill, you can fully expand it, outline the strokes and then use Merge: