Originally Posted by Cymru
Yes it is a Typo; a contact spray contains an electrolyte (such as a metallic salt) to increase the connection between two, well, contacts. Used on inert gold, that might be ok, although Hg might be better from a chemical stand point. They also contained a reducing agent (such as a sulfite) to de-oxidize corrosion. They were never in favor just as a can of flat-tyre "fixer" solves one problem but causes another. There is sold the de-oxidizer alone, but a stiff brush into slots, and a rubber eraser on contacts is more affective. That and Iso-PrOH is safer as the contact spray can jump a connection across the wrong contacts if too much gets in. I don't think they are sold any more.
For rusted parts stuck together (nuts & bolts, frozen pistons, etc.) the top product is called "Kroil" made by Kano Laboratories in the states.
Thank you for your in depth explanation, Cymru!
So what should I use, generic rubbing alcohol or isopropyl alcohol? Orrather, can I safely ue regular alcohol? I don't have isopropyl.