Not to kick this totally irrelevant subject around anymore, but just to make
a little correction: all the formulae I have show sodium bisulfate (a quite
acidic compound, often substituted as a weaker alternative for sulfuric
acid) as the active ingredient. In fact, at one time drain cleaners were
made up of powdered bilsulfate and powdered aluminum (aluminium: uk) to
create gaseous pressure. OK, that's enough - this has nothing to do with alt
photo (except perhaps sodium bisulfate would make a great tray cleaner).
Sil Horwitz, FPSA
Technical Editor, PSA Journal
silh@iag.net