Empty the baby bottles of their contents. Rinse out the bottles.
Put the stopper in a sink drain. Add two to three drops of liquid dish detergent into the sink. Fill the sink half full with hot water.
Submerge the baby bottles and nipples into the hot water. Leave the parts to soak for 20 to 30 minutes.
Scrub the inside of the baby bottles and the nipples with the bottle brush.
Rinse the parts of the bottle with water. Place the items on a drying rack or towel to dry.