that surface rust at the fuse terminals is easily treated with many OTC rust products. even soaking in vinegar water, scrubbing with an old tooth brush, and then lubricating the newly exposed metal fuse clips with a silicon grease will last... 30+ years, I'm predicting.
but to soak the fuse (box, more or less) in an acid solution may require pulling the whole dash assembly from the car, so the wiring harness may be extracted. in the end, it's the same amount of work, just without the replacement wiring harness.
a dremel tool with a tiny wire brush may do the trick without removing anything (but the fuses) and when you put fresh fuses in, lubricate them with the dielectric (silicon in many cases) grease.