I got these instructions from a Google search of Sistan on the second page.

""Richard Knoppow" <dickburk@i...> wrote on Mar 01, 2001 Original version

The instructions are: For film and fiber based prints dilute 25 ml of
Sistan in 975 ml of water.
For RC paper dilute 50 ml Sistan in 950 ml water.
Soak prints or film for one minute. You must squeegee after the
treatment to remove excess from the surface. Any excess or droplets
may result in staining.
There should have been instructions on the bottle and the box it
came in.
Sistan contains some wetting agent.

Sistan works to some degree but is not as effective as toning with a
sulfide toner.
---
Richard Knoppow
Los Angeles, Ca.
dickburk@ix.netcom.com"

This guy knows his stuff Process wise.

lee\c