Ok, so it took a while, but vinegar worked just fine! I was out of town for a week or two, so it sat for a good while. I did check it after 1 day (before I left town) and it didn't seem to have come along very well, but after 2 weeks it was done! Here's a photo, and one of the original nuts with the coating still on for comparison. As I was drying off the hardware, surface rust was visible, so I guess that means I got all (or most) of the coating off.
Today I went to the local restaurant supply store and picked up some Citric Acid (powder) and that stuff works alot faster, after an hour it looked like most of the coating was gone. So, I think I'll use the Citric Acid from now on, it's alot faster. And just like vinegar, it's safe to dump down the drain, and you don't need gloves like some of the more harsh chemicals (muriatic acid and what not).
The Citric acid didn't seem to cloud up and get all brown like the vinegar did, makes it easier to tell when the parts are done