It is advised not to place your Chilly bottle/cup into the diswasher. It is recommended to clean your Chillys bottle/cup regularly with hot soapy water and avoid using Milton sterilising fluid as this can affect the bottle. For a very thorough clean please use water with a teaspoon of bicarbonate soda. Whilst Chilly's bottles/cups are made of high-grade stainless steel which preserves the flavour and freshness of your drinks, failing to clean Chilly's bottles/cups and their lids can lead to a smell or taste developing. For this reason, regular cleaning is highly recommended.