The NEET Bottle is designed to destroy bacteria and viruses in the hardest to reach areas, where these microorganisms love to grow. We recommend to regularly hand wash the upper lip of the bottle with warm, soapy water to remove any physical build-up or residue. If you use other liquids such as tea, coffee, or sugary drinks in your NEET Bottle, we recommend to hand wash with warm soapy water after each use.