Brian,

Typically in processing fiber prints, for archival purposes, one uses two fixing baths. The first would be the 32 oz of Thiosulfate per gallon of water mixture, which would then have the Bisulfite added to it. The second fixing bath would have the Thiosulfate at the same dilution without the Bisulfite.

The second fixing bath of this printing session would be saved and it becomes the first fixing bath of the next printing session by adding bisulfite to it. So each printing session you would use a fresh mixture of the Thiosulfate/water mixture for the second fixer bath and add the Bisulfite to the first (saved) batch from the previous session.