Invest in one of the CHEAP band sanders/grinders from Harbor Freight when they are on sell for $19.00.
You can get belts for them from differenat places up to about 6,000 - 12,000 grit, and can also get lether belts for stropping.
Remove the plate from behind the belt and you can put a good convex edge on your khukuri with it...
Then it will cut BETTER than a hatchet of the same weight...
HERE is a link with some examples and tips on chopping with a khukuri.
There is also a LOT of information HERE.