I remember your other thread you had a moldy/musty smell going on, and didn't it take around a week for the soil to dry from the flush? As for treating root rot (if that's what it even is), I've read that adding hydrogen peroxide to the soil can help get oxygen to the roots and disinfect the soil. But hopefully somebody with first hand experience will come along and give you a proven plan of action. I would hold off on watering until then.