a way to clean metal (zippo colection) using materials at home.?

Answer 1

Brasso. comes in a blue and, white can. it will last awhile and, wont damage Your lighters.

Answer 2

This may sound silly, but try using coca-cola. I've seen it do amazing things with certain metals, it's a low-cost shot. Mythbusters had a special on it's uses and the multiple uses were phenominal!