I don't have any large negs but it seems to me the washing you describe is for final wash - which is/can be done in room light. Therefore, any procedure you like could be used: Tray, rotation, tank, dip & dunk, etc.
Originally Posted by mark
I think the essence of washing is the friction of clean water over a period of time. I think the Ilford system makes plenty of sense. Keep in mind the brunt of the washing takes place in the first bath. Time in the first wash is less important than the volume of water. You are further neutralizing the majority of the chemistry present and diluting it. That first bath contaminates very quickly and becomes useless in a matter of a few seconds.