Check Ilford's site, they recommend a similar procedure for film washing. They state that removal of fix is by (insert chemistry term for chemicals moving from high concentration to low concentration - osmosis? diffusion?), and not by the flowing water. For film, they recommend 3 water baths: 10 inversions (agitation for small tanks), 5 minute rest, change water, 20 inversions, 5 minute rest, change water, 30 inversions, 5 minute rest.