First learn how to take apart a Smith & Wesson...
Unscrew the sideplate screws with a proper screwdriver and remove the grips.
Then - using a mallet, tap around the frame, until the sideplate 'pops' free - do this over a towel, since they can pop all the way out.
Loosen the crane screw, and pull out the crane and cylinder.
The rest is pretty self-explanatory - the above was just a reminder.
If you don't want to use Dawn - which is an excellent grease remover - use Lighter Fluid or Nail Polish Remover, and be prepared to be amazed.
You can leave everything in place, if you do this - with no fear of 'any' water droplets remaining in hiding.
Following that - you can 'hose' it with WD-40, since it'll blow any little pieces out - and drain.
Follow with a good lube - reassemble and cycle.
When you re-install the sideplate - fit it into the recess and press lightly - don't try to push it in all the way - put your screws in place, and tighten equally, and watch as the sideplate fits itself into place completely.
Good Luck.
Any questions - PM me.
Vaya,
Scouts Out!