bolt and hardware cleaning

I sand blast them but it is a bit cumbersome to run a big rig out on the ground for small parts.
I'll prob get me a small blast cabinet soon for small stuff.

Chemical cleaning:
If they have paint and grease on them, you'll need to degrease and rinse b4 you de-rust.

I'd get a metal 5 gallon bucket and a steel basket that fits in and holds lots. Then a pound of lye and a bottle of dawn dishwashing liquid. Fill w 3 gallons water and add to that.
Wear eye goggles and gloves. This won't be too strong but it will be bad for the eyes.
Let bolts soak for a couple weeks, occasionally sloshing them. They'll come out bare.
Rinse well.
Then soak in evaporust or ospho diluted half w water for a few hours. ospho and others leave a black appearance which is decently protective against rust.