Quoting EvilMaxWar, reply 8Most of the times dirty contacts are the problem.
Alcohol works fine on things with exposed contacts... microswitches don't normally have exposed contacts, so even if that is the cause, dumping it on top isn't liable to do much. My experience has generally been that button failure is due to plastic part wear, or the solder joints cracking. YMMV.
Your typical microswitches are not hermetically sealed. You can spray inside them with contact cleaner spray usually from around the button opening. I agree the chance of alcohol getting to seep inside by pouring it on top of mouse openings are very slim.
I guess I should not have suggested that, but not much to lose if OP was going to buy a new mouse anyway. Personally I would just open the mouse and clean the switch directly, It is worth a shot.
Hell, simply mashing the button energetically might do it. I have seen dead switches and bad solder joints of course, but very rarely compared to dirty switches. I have never seen a mouse with a bad switch, dirty mice and broken cords, yes. But not broken switches.
However I recently replaced all the microswitches in a vintage Roland synthetiser, about 50 in total. Even after cleaning they still worked badly. But it was this type of button, those suck.
Now I am curious about what OP did, hehe.