George,
You're the 2nd guy who has done this recently and I wonder where you get your information from. Boiling in bleach is the most aggressive action you can take on a gun.
The proper way to do a lock is to polish it, but it needn't be a high polish as it will be destroyed. Take your lock and apply some type of resist to areas you don't want pitted, for instance the backside of the plate. You can use beeswax, fingernail polish, shellac, or anything that is easily removed later.
Coat the parts you want to pit with a cold blue such as Birchwood Casey. Lay the plate on a cotton cloth with the resist side down. Spritz the lock with bleach, fold the cloth over it, and then dampen the top of the cloth too. High humidity days are best. Let it sit for an hour and check progress. If you want more action, spritz the plate again and redampen your cloth. Always keep the top of the cloth damp. Do this until you have achieved the look you are wanting. 4/0 steel wool the surface. It should be gray if that is your desire. If you want to age it, reapply the cold blue and wool it back again, leaving your aging color where you want it. Rinse the plate, remove the resist, and oil everything.