I made a post a couple years ago asking how to remove carbon from the bolt and bolt carrier. My conclusion then was to try to scrape the carbon with whatever tool I could find that would work, but nothing I had worked well. I noticed an advertisement in a gun magazine for the Real Avid AR-15 carbon scraping tool. After reading some reviews on Amazon I decided to give the tool a try. While ordering the Real Avid tool, I noticed the "what others also purchased" on Amazon included an interesting tool for the same purpose made by Kley-Zion. I ordered both.
I cleaned two bolt carriers, bolts, and firing pins that were almost equally carboned up, one with the Kley-Zion and one with the Real Avid. I found both did the job well and reduced the carbon removal time to less than a minute and did a good job. In the past I would spend a lot longer attempting to removed the carbon and was never able to reach or remove the black crud from the hard to reach places in the carrier or the baked-on carbon on the bolt shoulder.
The Real Avid tool tool cleans more hard to reach places on the bold carrier group and has a built in pin puller, while the Kley-Zion tool scrapes the carbon from the bolt shoulder slightly better than the Real Avid. If I had to recommend one, I would say get both and enjoy the better aspects of each .
Kley-Zion: