Indy,
You use the K pouch system for irrigation...tap water is just fine and when out an about or travelling I take a child-sized water bottle with a sippy-tip on it to fill or rince things out or fill my syringe...makes public toilets and planes easier to handle.
If you find an irrigation bulb (sort of rubber of silicon) they you may be able to squeeze the water into the tube directly (I do it in emergency situations with the water bottle but then I throw the bottle away afterwards).
Sharon