The bane of my existence was trying to clean the "Push Push" switches in banks on stereos, tape recorders etc.
A tech friend told me about this tip, after I was loudly grousing about what a pain in the rear they were to try to clean
I had tried drilling into them and injecting cleaner- plastic bits got into them and jammed them, disassembling them- you don't even want to try that, and an ultrasonic cleaner.(Getting them dried out was a real pain too.)
My buddy told me to take a very fine tip soldering pencil and carefully melt a hole in the back top corner of the switch, just big enough to put the spray nozzle tube of a cleaner into, then seal it up with a bit of silicone RTV.
It worked like a champ!
I did find out that while the bit of melted plastic was still hot, to push the switch a couple of times in case the plastic blocked the switch workings inside.
It makes them really easy to re-clean & re-lube in a few years too. I never had this fail or cause problems unless someone had run high current through the switch and burned the sliding contacts.
I would suggest using an old "garbage" pencil iron, as trying to solder with it after using it to melt plastic is not a good idea. You can even grind down the tip to a smaller diameter if desired, or thread a piece of house wire and screw it into the end of the iron.