For metals gourds, wash with warm soapy water. For calabash and cuia gourds, rinse with hot water and allow to fully dry before next use. Natural material gourds will naturally darken and cure on their own (some minor mold and mildew are normal) and will be fully cured within 3 months.
Clean metal bombillas/bombas with warm soapy water. If filter is removable, use a bombilla brush to clean the inside shaft. For a deep cleaning, periodically boil in water and baking soda then rinse and allow to fully dry.