Thanks to Charles Lewton Braine, John Burgess, “mfleet” & Peter Rowe,
who collectively and convincingly persuaded me that Sparex is in fact
sodium Bisulph-ATE and not sodium bisulph-ITE.
Armed with this new orchidean knowledge I just now bought a kilogram
of it, in the form of swimming pool chemical, at the hardware store
for 3 dollars - which would likely have cost me about 20 dollars
bought as orthodox Sparex.
And yet the clerk at the wine store where I bought the sodium
bisulph-ITE (the wrong stuff) did tell me that a local manufacturing
goldsmith company bought it there also. He seemed to be quite certain
of his Makes me wonder if they may be pickling with the
wrong stuff on an industrial scale.
Cheers & thanks to all