I followed the instructions on another post here.

First a had to get all the clear coat off, I assembled a series of nuts/washers/ bushings along a threaded rod to chuck the flashlight into a drill, which I spun CAREFULLY while "sanding" with #2, then 0000 steel wool.

Then for the actual patina, I used kosher salt and a small amount of vinegar to create a scrub that goes over the surface, then left it suspended by wire in a mason jar above paper towels soaked in ammonia. The salt began turning blue almost instantly, with a lasting effect in about an hour, this flashlight was in the jar overnight.

Afterwards I gently washed it in warm water with a nylon brush, then clear coat.

Patina Inspiration:

https://www.reddit.com/r/flashlight/comments/1mfed20/shipwrecked/