I usually leave my FB prints (for 24 hours) in the washer and fully wash them during the next day's printing session. If I wouldn't do that, my printing sessions would last 5 hours and lead me to 4AM. As it is, I stop printing at 2AM and go to sleep.
All my prints have held very well. Actually, I'm sure that leaving them soaking for 24 hours washes them even better but I can't test this.