As soon as you get your Watercell / Pack Tap home, wash it out with warm water and dish soap, rinse it thoroughly and dry it completely. A Watercell should be hung to dry upside down using the lash points on the side. A Pack Tap should be positioned so the opening faces downwards - a spacer in the form of a repurposed wire coat hanger or the end of a kitchen spoon will allow air to circulate through the bladder.
Failure to get either of these products completely dry prior to storage may result in internal mold growth.
Do not use boiling water to clean either product. The heat welds of the Pack Tap will fail instantly.
If your Pack Tap or Watercell has residue from fruit juice or wine inside, and warm water and dish soap do not remove it, do not use a bleach solution to clean it out. If you do, it will taste like bleach for many uses afterward. Instead, use effervescent peroxide tablets to remove any sticky stains.