Old timer at the Seattle shop told me to never use WD-40 on a sticky shutter.
He said it would attract dust and gum up worse in a month. I ignored him on a cheap Pentax K1000 last year, just wanted a quick fix. Sure enough, the shutter is now completely seized and I have to do a full strip-down clean. Anyone have a better solvent they trust for that kind of light lubrication?
The old guys always know... you pay for the quick fix later. My go-to is lighter fluid on a q-tip for shutter blades, it dries clean. Learned that one the hard way too.