Great $2 buy. Good for derusting experiments. I've used many methods for derusting. Results always vary.
The beet sugar (molasses type process) works well for long term treatment. You can buy the dry mix in a 50# bag for about $10 at a feed store. It is added to cattle feed to entice eating. Mix a slurry like pudding- drop in your rusty stuff, stir occasionally, add water if needed. I usually have a 5 gallon bucket with it behind the garage all Summer. You can dump it on an unused lawn area with no ill effects, hose the stuff off, maybe scotch bright it with some water and be surprised with the results. The toolbox may be a candidate for this a month or more is not unusual, but it is cheap and easy.
The vinegar bath can be assisted with the purchase of a garage sale crock pot. Set the heat at the lowest, add the stuff at night, check in the morning. Seems to work better than a cold mixture. Whatever you do, DO NOT use the household crock pot!
I played with the electrolysis once, not sure the nasty mess & potential risks are worth the effort.
All of the above methods produce results that will flash rust immediately if not treated as soon as rinsed. You need to coat, oil, wax, or polish to preserve the newly found treasures.
