Here is an MSDS for Perma Wash that lists a couple of ingredients: https://art.illinois.edu/images/docu...-Permawash.pdf
Ammonium sulfite and sodium ethylhexyl sulfate are the two listed.
Ammonium sulfite is close to the same sulfite ion per molecular weight as sodium sulfite. I don't know if ammonium sulfite acts faster or more efficiently than sodium sulfite. I washed longer than their (IIRC) somewhat absurdly short recommended wash times. Perma Wash is a little more convenient and/or stock solution is longer lasting than Kodak HCA, but if one is making wash aid from sodium sulfite that's less of an issue.
I have films and RC papers from 20-25 years ago that were wash-aided with Perma Wash and don't seem to have degraded, but no fiber base papers, and I didn't do residual fixer tests.
(By the way, why does ammonium thiosulfate (rapid fixer) fix faster than sodium thiosulfate? I wondered if that was related, but couldn't find an answer, even though it is presumably well understood.)
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