A working whistle is arguably the most useful tool a referee has while trying to maintain order on the court, rink or field. Cleaning the whistle thoroughly after each use achieves more than just preventing bacteria from being transferred into your mouth. Soaking the whistle also prevents the pea inside of it from drying out. The method for cleaning a metal whistle varies from that used to clean a plastic one, in order to prevent damaging the whistle.
Wipe dirt and debris off the whistle with a damp cloth.
Place enough water inside a cooking pot to fully cover the whistle.
Put the pot on the stove. Turn the stove on high, and wait until the water comes to a boil.
Place the whistle inside the boiling water. Soak the whistle for about 5 to 10 minutes.
Turn the stove off and wait until the water cools. Remove the whistle from the water and let it dry overnight.
Wipe the outside of the whistle with a damp cloth.
Pour enough antiseptic mouthwash into a clean bowl to cover the whistle.
Soak the whistle for roughly 30 minutes to eliminate bacteria.
Remove the whistle from the mouthwash. Rinse it under cool running tap water for about one minute.
Place the whistle on a clean towel. Let it dry overnight.
Place a dry whistle inside the freezer when it's not being used to prevent bacteria from appearing inside or on the surface of the whistle.