[dancqu]

...one of the early proponents of the sequential dump and
fill showed mathematically and in practice that this method
was not as effective as a stream of continuously running
water for washing film or paper. PE

And Mason's measure of effectiveness? Successive changes
and soaks though DO work to make more efficient use of
the little water used. A method which uses little water
yet is a practical, easy, quick, way to wash.

I don't believe Ilford in recommending their three changes
of water with agitation have thrown us a bum steer. Dan