Use a triangular file as explained above. The problem with chasing is that the chaser will also want to pick up the bad thread and you'll be further establishing the cross thread.
I generally don't bother trying to save the first threads on hubs, There's plenty of thread engagement, so I use a flat file to create a bevel at removing the first thread or so. This not only solves the immediate problem, but reduces the chance of cross threading later on.
BTW- a half mill file is best for this kind of work because it leaves a better finish.
__________________
FB
Chain-L site
An ounce of diagnosis is worth a pound of cure.
Just because I'm tired of arguing, doesn't mean you're right.
“One accurate measurement is worth a thousand expert opinions” - Adm Grace Murray Hopper - USN
WARNING, I'm from New York. Thin skinned people should maintain safe distance.