I'm only familiar with HT2. P. permanganate
is typically used for reducers, tray cleaners,
and stain removers. Not sure then why this would
be an ingredient in a washing test.

Calling Richard...

  HT-1 and HT-1a (slightly modified) the test using
Permanganate, is a very old one and is not considered
adequate. This test measures the amount of hypo in the water
draining off a print or film and does not give an adequate
idea of the amount of hypo remaining, especially in fiber
prints. It was replaced at least fifty years ago by the
silver nitrate test. This is applied to the emulsion but
will also work on the support side. The silver nitrate
reacts with any remaining hypo to form silver sulfide, which
shows up as a yellow or brown stain. Kodak used to publish a
card with stain chips called the Kodak Hypo Estimator for
use with this test (and also the Sodium sulfide test for
residual silver halide). There is a more elaborate version
of the silver nitrate test for use with a densitometer but
the simple test is adequate to check for completeness of
washing.
  Since the test leaves a permanent mark on prints, even
when washing is complete, it is suggested that a test strip
be processed along with the prints for the test.

Here is the formula for the Silver Nitrate test.

Kodak HT-2 Hypo Test Solution

Water                        750.0 ml
Acetic Acid, 28%             125.0 ml
Silver Nitrate                 7.5 grams
Water to make                  1.0 liter

  To test place a drop of two in a clear area of the margin
of the film or paper and allow to stand for about 3 minutes.
Swab off. There should be little or no stain.
  Note, the untreated test spots will darken in the light
so the test should be carried out in subdued light and
comparision made soon after applying the drops.

  A liter of this solution is a lifetime supply. I
recommend making up no more than 50 or 100 ml at a time.
  Because the Silver Nitrate will react with halides in the
water its best to make it up with deionized, or at least
boiled, water. There should be no precipitate when makint it
up.
  The solution should be stored in the dark and will keep
several months.

  Search Google from this NG but not this NG for,  turner
horder fixer . A post there from 1991 details a few test
methods. Very interesting.
  From Google search for,  ilford permanganate hypo . That
site has a few very interesting articles.
  Turners' approach I think most interesting. I think it will
work with paper as well as with film. Dan