Mine never mentioned a waterpik either way. I have never used one but I'm curious why you couldn't use one during rad unless stressing caution about the sores that may develop in the oral cavity.

David

Age 58 at Dx, HPV16+ SCC, Stage IV BOT+2 nodes, non smoker, casual drinker, exercise nut, Cisplatin x 3 & concurrent IMRT x 35,(70 Gy), no surgery, no Peg, Tx at Moffitt over Aug 06. Jun 07, back to riding my bike 100 miles a wk. Now doing 12 Spin classes and 60 outdoor miles per wk. Nov 13 completed Hilly Century ride for Cancer, 104 miles, 1st Place in my age group. Apr 2014 & 15, Spun for 9 straight hrs to raise $$ for YMCA's Livestrong Program. Certified Spin Instructor Jun 2014.