I'm trying to clean up tension bolts before I assemble an engine and I'm trying to figure out the best way to get them clean. I tested things on a couple spares with bad results.

Setting them in a bucket of carb cleaner seems to remove the black coating on them – so I'm guessing this is a bad thing.
Letting them soak in a simple green solution for a few days takes care of the grease but leaves surface rust.

I resorted to washing them with simple green and a wire brush and finishing with kerosene on a scotch brite, and they still don't look great but they're better. I don't have a lot of spare time so if anyone has a better way to get these clean quickly without messing them up I am all ears. Thanks

 

i run a die over the threads. i use brake clean, or simple green on the head and then wipe down the shaft with the same rag.

 

I was afraid brake clean would take the coating off, but that definitely sounds like the best option. Thanks