Most people hate flossing. It's tedious, difficult, tiring and time consuming. Water flossing with what is technically called oral irrigators seems to be a good way to achieve good cleaning in between teeth, without having the trouble of flossing!
Studies have mainly looked at the Waterpik brand of water floss so it has the most scientific backing. The effectiveness of the plaque removal will depend highly on the power and stream characteristic of the water. Other brands may be inferior, I do not know.
Researchers have found that water flossing is effective in removing plaque from in between teeth and had better gum health than string floss.
So, water flossing is an acceptable method to replace floss! It is a significant investment with a quick online search showing me they cost around $140. If flossing is really too much trouble for you, water flossing is definitely a great tool for you; you will have less painful, faster and cheaper dental appointments!