Black stain spreading on keris during vinegar cleaning

[A. G. Maisey]

One of these days Jaga, I'm going to try Coca-Cola on a keris --- and a few other things.

There are some particularly nasty concoctions that some people in Jawa use make blades look old. Some of these devil's brews can eat a keris over night.

It is, I believe, meritorious to try different things, but it is even more so to try them slowly, gently and with care.