The other day I had a new car battery installed and the tech sprayed something from a spray can on the battery connections, he said if there was any corrosion left the color of the spray would have changed and I had the impression the spray also cleaned.
I don't know if that applies to NiCd corrosion.
No need to spray (never spray!) strange chemicals, probably not intended for this use which possibly make things worse.
To clean certain areas of printed circuit boards I use a thin hose, taped to a (water capable) vacuum cleaner.
While applying cleaning fluid with a small brush - usually demineralized water + isopropyl alcohol - I vacuum away the fluid from the board.
This way I can limit the cleaning fluid to the contaminated areas of the board, preventing it from spreading the contamination.
At the same time this technique removes ALL contamination, as the cleaning fluid isn‘t just drying on the board, but
completely sucked away.
Always suck away the fluid from the brush before dipping it into the fluid for the next dose, to keep the fluid clean.
This works well even with very high impedance circuits, where every little bit of residue disturbs the function.
Warning: Don’t do this with microphone capsule’s diaphragms.