Start with a hickory split and you won't have grain run-out
True. But downside is not everyone has access to good green hickory. Good rods are difficult to find. (I know, a member here is reported to be selling fine rods, I applaud that)
If you do split your own rod, I personally have never figured out how to make the rod nice and round without a blade machine. e.g. pencil sharpener type. Using that blows the whole intent of going for no run-out. Scraping with a knife will work but the rod will not be round or straight. Really, that's OK if you ain't looking for perfect or pretty.
All that said, difficulty of finding good hickory, run-out free, rods is why I went to Delrin for 90% of my shooting. Won't break, easy on the bore and, most of all, safe. My wood rods are saved for historic presentations and ronny.