i've washed 5x7 a few ways.
this first way i don't do anymore because i got rid of all my hangers ... but if you have film hangers, you can just leave them in a tank with water running and you will be okay.
the second way is what i currently do. (i tray process) after i do the perma-wash, i shuffle the film in a tray, fill-n-dump 20 times. haven't had any problems and the "residual hypo tests" come out clean.
if i had the $$ i'd get a negative washer. lot less of a hassle than standing there filling, shuffling, and dumping.