Use hot, soapy water and rinse thoroughly with hot water. For tough cleaning jobs, add 1/4 cup of baking soda to 3/4 cup of water per liter volume of your bottle or reservoir and shake for 30 seconds. Add 1/4 cup lemon juice, shake 10 seconds, and vent by loosening cap away from face. Repeat shaking and venting three times. Expel as much air as possible, cap bottle, and allow to soak 20 minutes. Rinse three times with hot water. Caution: When adding lemon juice to baking soda, effervescence occurs and will cause pressure to build in a capped Platypus product.