Paul, good point; dumping bath 1 after one 8x10 may be too conservative. My source for this procedure was the lab assistant at Arentz's workshop who sort of equated yellow clearing bath (even slightly yellow clearing agent) with exhaustion. Is there any research on when a pt/pd clearing bath is exhausted (ala fixer in Ag printing)? That would be helpful, but perhaps the concept doesn't apply. I do a 1 minute fresh-water rinse between KOX developer and clearing bath 1. I would have to rearrange things a bit, but I could do rinses between clearing baths.
Re the composition of Perma Wash. Like so many proprietary formulae the MSDS only shows a few ingredients; the rest are listed as "Trade Secret." The chemical family is shown as "Sulfites," and the two named ingredients are "Ammonium Sulfite, Monohydrate, less than 20%" and "Sodium 2-Ethylhexyl Sulfate Ethylhexyl Sulfate, Sodium Salt, less than 5%." On the bottle the label only says "Contains Ammonium Sulfite and Sodium Sulfite."
Wayne