A little bit of Endust for Electronics can go a long way.

Take these computers I got back in 2011: http://s93.photobucket.com/user/MacPlus512/library/New%20Macs?sort=3&page=1

There's an SE and a IIvx here. (There's also a second SE, which I parted out). Both the SE (with the blue light) and IIvx are parts of my arsenal of Macs to this day, with the SE used on a regular basis by students I work with. Both got cleaned up and the IIvx looks almost new.

I'd buy that PS/2 if I could just to show what a great machine it could be with a little love.