I am conducting a research on comparing the effect of water floss to regular dental floss and I am wondering how can I sterilize my tips between participants.
It depends on the type of water floss that you are using, the material which is the tip made of.
Ideally the tips should be disposable and you use one tip per patient (can be used multiple times for the same patient), you can look for Flosser Replacement Tips for Waterpik Water Flosser and see how costly are these tips.