:If you have a stained glass supply shop nearby, they have some patinas for changing the look of the "lead lines" on glass panels....the chemicals might be the same as mentioned above.

Watch out for No.1....I think it is the ammonia in the urine that does the patination. My sister once chose to use household ammonia to patinate a piece of brass overnite - forgot about it, then dicovered the ring had dissolved. So watch the time the object is in contact with the patina solution!