Nonfunctioning L or R Button

I took the DS Lite apart to look into it. The parts all lined up correctly, the button clicks down well but there is no response while in use. It slowly stopped working... thought it was tricky at first but then it gave up function completely.

One solution I am considering is using a cue-tip with 90%+ isopropyl alcohol and dropping some into the button and pressing it 200x to see if that fixes it...

If this is a bad idea or fails, what is the next step?