No, you should not water a plant with root rot until it has shown signs of recovery. Overwatering is often the primary cause of root rot due to waterlogged soil that lacks proper aeration, promoting fungal growth. Therefore, it's essential to let the soil dry out and follow a proper watering schedule, considering the plant's specific needs. If treating the plant for root rot, focus on creating a well-draining environment for the roots and monitor the plant's progress.