I have changed from water rinse after developing paper to a mild solution of sodium metabisulphite which is probably more compatible with alkaline/neutral fixers than the usual acetic acid. I use a Nova vertical slot processor that is designed for running water in slot 2 (the old "Chrome" model) but I found that it does take quite a bit of rinsing to ensure that the prints will be free of stains. I have blocked off the drain to that slot so I can fill it with my stop bath. If using FB paper you can't rush it.