They are washable in a dishwasher - yes, completely dishwasher-safe. Your bamboo straw has been sanitized in boiling water for 10 minutes and sun-dried.
To maintain bamboo’s natural structure and antimicrobial properties, please try to wash your bamboo straws after every use. A rinse with warm water should suffice, but you may also wash it with soap on a regular basis. A straw brush/cleaner can also be used.