Blue Brass

[Yosemite Steve]

I just googled blue brass... assuming you did the same. One youtube video... the first one is using a 50% solution of gum metal blue and distilled water. Another person soaked kitty litter with amonia and made a paste to coat the brass. As far as toxicity... metal oxides are generally not good in your body. Hope that helps

 

[Siggy-06]

Sounds to me they used ammonia to clean the railing.

 

[Unclenick]

You don't want to use ammonia on cartridge brass. It causes season cracking.