The fabric softener is usually added to the washing machine during the final rinse cycle.
When the washing machine reaches the final rinse stage, the fabric softener is flushed into the washing tub. This way, the softening components can fully adhere to the fabric fibers during the rinse process, achieving the effects of softening and anti-static.
Why not add fabric softener during the washing stage:
If it is added during the washing stage, the softener will be washed away along with the detergent, failing to achieve the softening effect. And if it is added during the intermediate rinse, it will be washed off by the subsequent rinse water. Therefore, the final rinse stage is the best time.