Floss and whiten at the same time with this Waterpik Professional. Just pop one of the minty whitening tablets into the handle, fill the water tank with warm water (definitely warm – trust us on this), and get going. Sensitive gums? You get 10 speeds to choose from, so you can start off with a lighter pressure and build up as your gums get used to it. The tank holds enough water for 90 seconds of cleaning, and you get 4 tips and a storage case to get you started. This one is mains-powered with a shaver socket, so there’s no recharging to faff around with, and it’ll work in hotel bathrooms if you can’t bear to be without it when you’re away.