hi---
hope i can help with your request. there are many
different schools of thought regarding the cleaning/polishing
of hardware. i personally do not believe that polishing hardware is
beneficial to its' look or value. i am a member of the antique doorknob
collector's club of america and wrote a short article addressing
this question. in that article are recommendations for
the cleaning you request. the article can be found in
the doorknob club's newsletter archive here:
http://antiquedoorknobs.org/NewsletterArchives.htmchoose newsletter #93 which contains the article "restoration versus
alteration" and download the file.
i believe if you will use the method in this article you will be pleased
with the results and the hardware will not be compromised.
good luck! stever