Go with *electronic* contact cleaner, not electrical contact cleaner, there is no residue with electronic. It costs more though. It evaporates really really fast, and is safe on most, but not all plastics.
Used it for years, along with fiberglass pencil to polish Atari 2600/Nintendo NES cartridge edges, and then on a tight weave fiberboard in the infamous nintendo slots to get rid of flashing screens due to dirty contacts.
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