totally disagree with this....if you use too much peroxide, it kills the beneficial microbes/bacteria in your soil and without those microbes/bacteria, you are severely limiting your plants potential...I never use peroxide unless my plants show signs of root rot, then I use 1 Tbsp/gallon...
as far as chlorine in your tapwater goes...my plants get it straight from the tap and have been for several years...doesn't seem to be hurting them...I have plants that are over 5 feet tall already and loaded with pods...
again, the number of plants you grow makes a difference as to how they are treated and what they get...you can futz with a few plants and "help" them along any way you want, but when you grow hundreds of plants, you just don't have time to painstakingly care for each plant...
remember this, the number one killer of chili plants is the person growing them...put them out, leave them alone (besides keeping an eye out for aphids/mites/etc), feed about once a month or so and they will grow well for you...your basic soil is the key to the "leaving them alone" statement...