"Joe Gwinn" wrote in message
...

One of the things I noticed when the detergents changed in ~2010 was
that coffee and tea cups developed a tightly adhering brown film
that
even hand scrubbing didn't touch.

Alconox, the original lab detergent (which I first heard of while in
college), is intended for hand washing of labware, and so I tried
it,
and noticed that the brown film peeled right off after a little
soaking.

Coffee and tea stains are still the waterloo of non-phosphate
detergents.

Alconox is also very good in ultrasonic cleaners.

Joe Gwinn

When I studied chemistry in the 60's the profs said that Tide was the
best lab glassware cleaner. Much of the glassware had unbrushable
shapes and any residue, especially of metallic salts, could poison the
next experiment.

http://www.pg.com/productsafety/msds...ated_03-13.pdf
Notice that the dose of alcohol that kills half the rats that drink it
is only 0.7% of their weight.

If Tide failed we resorted to hot chromic acid, which could strip the
pavement off the street.

jsw