Mike,
I know, I should do, after all the courses Ive attended over the years, that bringing the carpet back down to neutral is he aim. However, I also think this issue is somewhat overstated.
There are any CCs like me who built their excellent repeat business up over many years using traditional extraction detergents, doing a really good job and never did any special Ph reducing rinses at all. Always delighted clients, coming back for more and never any rapid resoiling problems.
Theory can on occasions be far removed from the praticallity.
Dave.