I'm soaking a very rusty fusebox right now in Evaporust. It's been about 1.5 days now, and about 50% done. I'm curious if it will work on the oxidized beryllium copper oxidation or not. Some rust is very crusty and the Evaporust doesn't seem to be working really well. I'll post the results in a few more days.
What also bothers me about Evaporust is that it will wick up into the wire insulation, and my experience is that it will take days for it to wick back out, even in the presence of a heat gun. For my work (different than concours restorations where time is not critical), I need to clean up fuseboxes within an hour or so.
After three days of soaking, I washed off a lot of crud, and put the fusebox back in the Evaporust. After six days, I washed the box well, used compressed air to begin the dry it, and then used a heat gun (which started the box to smoke a bit, so I turned down the heat). I stuck some paper towels in the backside to observe if any Evaporust wicks out of the wires.
This box was very rusty, and I would never have attempted to use it. Some clips still had some plating on it, so Evaporust appears not to affect the clip plating. What was left was severely pitted and corroded clips, which could have been cleaned down to bare metal with bead blasting in less than 5 minutes vice 6 days. I've had problems with Evaporust taking a long time to do its thing; perhaps my jug is too old and needs to be replaced. Six days is somewhat unacceptable.
Overall, I would not recommend Evaporust for fuse box clips, unless there is only a layer of patina and not true corrosion. Even then, you'll need something to protect the bare metal from future corrosion.
Other materials for cleaning that I've run across is Molasses and vinegar (not together!). I have used Diet Coke for a quick dip/cleaning, and that seemed to be OK on just dirty boxes with just patina.
So...that's the story from hereabouts. I hope you enjoyed the entertainment. Now back to your regular programming.