Jersey Flinter said:do not wash the lock with water
I've been shooting flintlocks since 1983 and after every shoot, without fail, I've taken out the lock, run it under hot water while scrubbing with an old toothbrush, shaken it, dried it with a towel then sprayed it generously with WD40 and set it aside for the excess WD40 to seep out while cleaning the rest of the rifle. Never had a speck of rust on any of my locks, internal and external.
I haven't been shooting that long, but for years I've been scrubbing my lock with a toothbrush and lots of water, drying what I can, then liberally spraying it down with WD40 or Barricade. Nary ever a speck of rust.
Being able to clean with water is great, as others here have noted. In the field in the winter, if I need to swab after shooting several squirrels, I just take a cleaning patch in hand, grab snow and let it melt in my hand into the patch, and down the barrel she goes. Better than carrying around a bottle of anything. :thumbsup: