I was in the hardware repair business, and used to keep a fibre glass brush. No solvents required. The brush came enclosed in a pen-like holder. The fibreglass brush shines up contacts like new, restores the shine without melting plastic or stripping metal coatings unless you're trying to. You need the fibreglass, not copper or anything else. Be gentle.
https://www.amazon.co.uk/Scratch-bru...ps%2C72&sr=8-5

Slackware-12.0 sounds good. If something absolutely won't boot you can try tomsrtbt if you have a dood floppy. It reformats it to 1.82MB, and writes a libc5 system with busybox. THAT won't run out of memory!