i thought PB blaster was not flammable or not as flammable as WD40.
have you tried a combination of vacuum cleaner, wire, and air gun from air compressor?
have you tried an actual "needle" like a larger size sewing needle? vs wire that may bend?
you might try, just taking key switch out (dismantal the dash, unhook wires) and pull entire switch out. so you can turn it upside down, and slightly tap it on something. to see if any dirt falls out.
having it upside down so stuff falls out while using some sort of spray, or air gun, or like. vs letting stuff fall back down into it, as you get stuff loose. would more likely help ya out better.
i would say call a locksmith. but by time you do that, it may be easier and cheaper just to get a new key-switch.