R.M.
I used to use it daily. I would swish it directly from the bottle into my mouth, then brush with toothpaste, without rinsing first. It definitely whitened my teeth, over time. Hydrogen peroxide is the main ingredient in many whitening products. Some brands or strengths of hp would make my teeth ache briefly, before I spit it out, but this wasn't common.
I can't guarantee you that it doesn't damage the enamel; that was one of my worries too, but it never seemed to, over about 10 years of using it. The only time my dentist commented on my enamel wearing away was my last visit after I had gone through a period of drinking a lot of lemon water, so I had to stop that. Lemons are highly acidic.
I haven't used hydrogen peroxide in a while though.