The best replacement for waterpik is flossing.

The best alternatives to waterpik are rated as following:
★★★★★  flossing
★★★★  floss
★★★★  sonicare
★★★  interplak
★★  airfloss
★★  electric toothbrush
★  moen
★  hydro floss
★  oral b
★  water flosser
★  brush first
★  dental floss
★  peerless
★  viajet
★  hydrofloss
★  flossing which is better
★  oxyjet
  sonicare toothbrush
  air flosser
  sonicare airfloss
  nettie pot
  sonic care

Your alternative for waterpik is not listed? Suggest!
Speaking about waterpik, one probably shouldn't forget about listerine.

Other search terms related to waterpik and their ratings are:

★★★★★ listerine
★★★ nasal irrigator
You have in mind a companion for waterpik and it is not yet here? Propose!

Google Trends

Scale is based on the average worldwide traffic of waterpik in all years. Click on graph for more.