Jammed Chromatic

[InfoBully@xxxxxxx]

I own a Huang Professional 1248 Chromatic that seems to have  arthritis - the
shifter (sorry-don't know the technical term) jams and has to be pulled back
and forth.  This turns this instrument into a frustrating piece of junk.  Any
tips or suggestions regarding lubrication to keep that "chromatic shifter"
smooth and supple?  I am sticking to my diatonics (which just sound much more
gritty and emotive in any event), but I would like to learn how to play the
chromatic.