Helpful adjunct... The water pik can be part of the regimen to maintain good dental health. But it is not necessary to accomplish this, and if other techniques are not followed, it is not enough (see prior answers about good basic dental care). As for peroxide, would not use straight peroxide on any part of skin or mucous membrane or in mouth: too astringent. Perhaps diluted, or combined with baking soda, may be ok.
Excellent! It is one of my favorite dental home care aides. When used properly it will reduce the amount of food and bacteria trapped between and under the gum tissue, better then most any other type of interdental device.
Very good. It is a good item to add to regular brushing and flossing, but make sure you put it in a medium setting, too hard can cause some damage.
WaterPik. Excellent. Use caution on angulation of the tip. It should be 90 degrees to the tooth so it causes a circular force around the neck of the tooth along the gum line. If it is 45 degrees it can put too much pressure causing a increase of the pocket depth. Have your dental hygienist demonstrate.