Need Help with my first Keris

[BluErf]

I'm going to wash a keris blade this evening, and I'm going to use grapefruit juice, straight from the tetrapak. As long as there is citric acid in the juice, it should work. Vinegar is fine, if you don't mind the smell. But based on my experience, vinegar gives a darker grey look while citric acid gives a whiter look. Not sure why.