I think I'm in the same group as most of the commentators on this post. I follow the Ilford method, but then leave the water for about a minute after each set of inversions before dumping.
And at the end of Ilford's method, I do an extra 20 inversions with fresh water and then add a drip or two of a wetting agent and then again leave the film in it for a minute.
Whether this extra set of inversions and one extra wash make any added difference when compared to the Ilford method - I doubt it, but like others I have fallen into this routine somehow and feel happy with doing it.
Before doing this for a number of years now, I used to use Paterson's washing hose and their advice of X amount of minutes in flowing water.
What ever the method I have used, none of my negs, as far as I am aware, have ever started to deteriorate, so I'm happy to carry on with my wash routine.
Terry S