Exposing the watered steel on a blade.

[Dmitry]

There are several ways of doing it that I've read about, but have never done it myself. I have a very beautiful tulwar that has vestiges of the watered steel pattern discernible on the blade, and I'm sure there's more hidden out of sight.
What's the easiest way of exposing the rest, preferably with non-toxic, accessible chemicals, and preserving it?
Thanks.