I just finished turning one of these blanks this past week. I found that I had to use an EXTREMELY sharp skew and turn at the highest speed my lathe will go, 3900 RPM. I turned an upper barrel first, and experienced some chipping out of the beans. When I turned the lower barrel, I soaked the blank in thin CA after every few passes with the skew, and this technique greatly improved the results.
After I sanded the blanks, I wiped them down with a little CA accelerator to help clean off the brown streaking from the sanding process. If you're good with a skew, you can probably avoid this. I'm not. Finished with a CA finish.