I like to take a small amount of rubbing alcohol, 70+% iso or similar (not acetone, lighter fluid has worked for me in a pinch too) and mix it with a small amount of graphite. You want an almost slightly runny paste.. I dab a q-tip in and gently swab the blades, let dry and fire it over and over again. Shake it out/etc. You don't want graphite floating around.

YMMV.. it helped an older graphex shutter for a while but the real problem was the spring. Eventually all speeds faster than 1/30th or so fired at the same speed (like 1/30th), but all the slower speeds work fine. 1/1 is like 2/1.
I still use it, amazingly.. the glass looks like someone (not me!) cleaned it with a brillo pad or took it to the beach. Ah well.