Available at Amazon, eBay and CAIG Laboratories.
I use DeoxIT to help restore retro computers and electronics in a lot of my videos and although this is not a sponsored Ad, I have provided some links below to help you find some for yourself.
DeoxIT cleans out the crud and light corrosion while lubricating the contacts and helps improve conductivity. Adding just a little to a connector can reduce intermittent connections, arcing, and RFI as well as wear and abrasion. It is safe for use on all metal connectors and contacts and will not harm plastics so it won’t damage your vintage computers or electronics.
I have used it to clean and lubricate chip sockets, edge connectors, power connectors on circuit boards and even clean scratchy POTs on monitors and older computers. Older electronics can build up corrosion on the connectors over the years and a little bit of DeoxIT on the socket or connector often helps eliminate the corrosion and establish a good connection again.
Spraying a little on the socket before plugging in the game cartridge not only helps with establishing a good connection but also lubricates the connectors, making it easier to get those cartridges in and out.