Remove the fabric softener dispenser from the washing machine. Some dispensers simply lift out while others require you to squeeze the sides of the dispenser as you lift.
Mix 1 gallon of hot water and 3/4 cup of chlorine bleach in a bucket or sink.
Place the fabric softener dispenser into the solution to soak for one hour.
Remove the fabric softener dispenser from the soaking solution and rinse it under clean, running water.
Moisten a slender scrub brush with nylon bristles. Add a couple drops of liquid dish soap to the brush as well. Use the brush to scrub the inner barrel of the dispenser to remove any lingering fabric softener residue.
Rinse the dispenser once more and dry with paper towels or let it air dry before returning it to the washer.