How to fix keyboard malfunction (random key press) without intrusive

On my MacBook I just started to face an issue where the “.” key would print “-.” even when shifting and after multiple restarts. The only reason this could happen is due to (dirty) tap water droplets (like very very small) got into the laptop, either into the key or through the trackpad, bridging the matrix.

This problem seems to have gotten worse now. Not just the . key, but now keyboard viewer shows the dash key as being held down unless a certain combination of two keys, like ./ or oi or kl or op, is pressed which then results in the key being shortly unpressed and repressed.

I understand this is a precarious situation, and I don’t even have AppleCare, but is there a method besides a 800$ replacement of the top enclosure to possibly clean the issue out? I’d usually use isopropyl alcohol but since I don’t know the actual area of “damage” I’m not sure where to apply it and would rather not coat the entire laptop.

As far as I know, the corrosion, if any, doesn’t seemed to have eaten anything, since the electrical traces still seem to be functioning and it seems that the issue is localised to the dash key matrix connection. Please correct me if I’m wrong though. I’m traveling and don’t really have access to any way of opening up the laptop until I get back. It’s also the only computer I have and I need to be able to access it, so is using it safe as well?

TLDR: is there a way to fix double key press without paying full cost? Can laptop be used during this damage?