I used a couple different products back in the '70's -'90's for cleaning switches and enhancing noisy contacts, but for the last 20 years I have been quite happy with Corrosion-X. I've perked up a lot of stereo's and re-animated a lot of sunken RC boats with this stuff...
https://www.amazon.com/Corrosion-X-90102-Anti-Corrosion-Lubricant-16-Ounce/dp/B003HFTI0S/ref=asc_df_B003HFTI0S/?tag=hyprod-20&linkCode=df0&hvadid=309811990469&hvpos=1o1&hvnetw=g&hvrand=15568617493267798440&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9015121&hvtargid=pla-457793615458&psc=1
If it hasn't been opened recently, definately vacuum first.
Unplug what you can, one end at a time, so you can't get confused. Paint the connections with corrossion-x, and re-assemble. Move on to the next part and repeat. Take your time and don't get ahead of yourself. If you cannot paint all the switch mechanisms, you may be able to squirt them, and actuate them repeatedly while they are soaked, and then use compressed air to blow the excess off the switch housing, or it may drip later. I squirt the Corrossion-X in a beer cap and use a solder brush to apply it.
Regards,
Bil
https://www.amazon.com/Corrosion-X-90102-Anti-Corrosion-Lubricant-16-Ounce/dp/B003HFTI0S/ref=asc_df_B003HFTI0S/?tag=hyprod-20&linkCode=df0&hvadid=309811990469&hvpos=1o1&hvnetw=g&hvrand=15568617493267798440&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9015121&hvtargid=pla-457793615458&psc=1
If it hasn't been opened recently, definately vacuum first.
Unplug what you can, one end at a time, so you can't get confused. Paint the connections with corrossion-x, and re-assemble. Move on to the next part and repeat. Take your time and don't get ahead of yourself. If you cannot paint all the switch mechanisms, you may be able to squirt them, and actuate them repeatedly while they are soaked, and then use compressed air to blow the excess off the switch housing, or it may drip later. I squirt the Corrossion-X in a beer cap and use a solder brush to apply it.
Regards,
Bil