Yes, you may use a water irrigator alongside your use of OraMD, but not to use OraMD inside your water irrigator. We suggest to use the irrigator prior to brushing with OraMD. OraMD is made of botanical oils and will separate and sit on top of the water in the tank. Also, some plastic components in oral irrigators will not stand up to the potency of OraMD's powerful botanical oils. If you use OraMD in water irrigators, rinse the irrigator for 20 seconds in warm-hot water.