I dropped the front valance on my 73 LDO and ended up with 10 rusted and greasy bolts and accompanying fittings. I couldn’t bring myself to re-use them without at least some type of cleanup. I soaked them in a plastic disposable glass in 10% vinegar, the kind Home Depot sells for cleaning purposes. They soaked overnight and then I gave them a shot of WD40. I’m satisfied with the result but what else works well out there? By the way, the bolts require a 7/16 “ wrench and the two bolt heads furthest to the front have very little room around the head. I was able to fit a small Craftsman11 mm “ ignition type” wrench. They needed a good soak in Liquid Wrench to get them to turn after 49 years.
when I go junk yarding, I save all the bolts and clips that I take off to remove what ever part I am sourcing. I have probably 10lbs. of extra bolts, washer and clips in a plastic tub.
Depending upon the amount of rust, I may soak something in 100% white vinegar for 3-4 days. It is a good rust neutralizer but mediocre grease/grime solvent.
You can also buy those bolts and clips new at Ace Hardware or Fastenal. Sometimes, it isn't worth the time and effort to clean the old ones...
I tumbled many over the years to clean them up. If they needed color touchup - a good flat black works well or if they should be silver or yellow cadmium, Eastwood makes some great products. If doing a show car - AMK sells kits to replace everything with new, correctly marked and colored bolts and screws. It is totally worth the cost for new bolts if doing a really good car. Example of AMK kit
A wire wheel on a bench grinder is hands down the fastest way. I have used different solvents and seen the tumblers in action. The wire wheel is the only way I clean. You're not going to be able to clean the inside of the clips and you must be careful because the wheel will pull the parts out of your hand. Charlie
The drawback is that it removes the plating as well as the dirt, which makes them more prone to rust...
For ones that are painted, I toss 'em in the sandblast cabinet. If they were natural there's cast iron, stainless steel & other metallic paints.