For rusty nuts and bolts, drop them in a plastic coffee can and cover them with "The Works" toilet bowl cleaner. Let them soak a 1/2 hour or so, swirl them around a few times during that time. When the rust is gone, rinse them in hot water, put in another plastic coffee can with a couple of spoons of baking soda, swirl them around, let them soak 10 minutes or so, and rinse them in hot water again. Works great, and the toilet bowl cleaner is cheap.
I have done the electrolysis before with good results. I started out with the battery charger which was just a waste of time. Switched to a DC welder set@ 5 -10 amps in one hour intervals, and got much better results. I did some snow plow parts that had areas that were impossible to wire brush. Got to be careful, the water will get hot, and it produces hydrogen in the process, so outdoors, or near the open shop door is best. I found it works great for parts that have chips in the paint, and the rust is undercutting the paint. If the part had surface rust on it when it was originally painted, the paint will come off in sheets. The best part is the process ONLY removes rust. So if you have a thin part, that sanding or blasting would destroy, you can strip it this way. The same goes for powder coated parts. IF they had surface rust on them, the coating comes off in sheets.
I made a frame from some round 3/8" stock to fit a kitty litter bucket, welded it together, and I hang the part to be stripped in it. That way the part is surrounded by "electrodes" and removal is much faster. Rebar is good for cheap electrodes. I also have the bottom of a 55 gallon plastic drum I cut off, and use for larger parts. For lye just use a scoop of Arm & Hammer Super Washing Soda available at most grocery stores. It's cheap too. Yes it can be messy, but better than the rust and paint dust all over the shop from the brush on an angle grinder, and it gets into places you can't. I just rinse the part and use a maroon scuff pad to clean it up.
Hope the info helps!
Here is my first attempt at it:
Electrolysis - Rust Removal? - Snowplowing-Contractors.com - Let's Talk Snow.com Discussion Forums
~Chuck