What do you have for nagura for your Jnat? If you only have a tomo nagura (or are using a diamond plate) to raise slurry, it will never be much more than a finisher. A set of asano Mikawa nagura (botan, tenjyou, mejiro) will let you do everything from minor bevel setting to finishing.
Did you use any slurry when trying to touch up your edge, or just plain water?
Here is a post I wrote a while back explaining how a Jnat is used with nagura slurry:
http://straightrazorpalace.com/honin...ml#post1648467