Use warm water and soap free from oils or synthetic fragrance and wash your cup for 20 seconds. Be sure to get the air holes unclogged and cleaned. Do not use tea tree oil, scented soap, castile/peppermint soap, oil-based soap, rubbing alcohol, antibacterial soap, hand sanitizer, dish soap, hydrogen peroxide bleach, or harsh chemicals as these may damage the silicone and cause irritation. If irritation occurs, discontinue use and consult your physician.
Sometimes you may want to do a deep clean. To do this, boil the cup for 10 minutes in an open pot of water. Do not leave the boiling pot unattended. Use tongs to ensure the cup does not touch the bottom of the pot. If you burn your cup while boiling, your cup may no longer be suitable for use and should be replaced.