I had the same problem and blew some electrical contact cleaner in the crevices surrounding this area. Based on the video above I knew the issue was buildup on the contact points. I had already purchased a used switch and disassembled it to clean it so that helped me know how I could best insert the spray nozzle straw. An avionics friend of mine made the suggestion to try this. It does sometime still not respond perfectly but it's so much better. Who knows? Maybe you'll have complete repair with this hack. It's definitely a low cost option to try beforehand if you haven't already replaced it.
Also I suggest putting the switch in various positions during the spraying to get the best chance at accessing these contacts. I believe I had the car battery detached and let it sit for a several days after as well.