I've tried looking it up, but most instructions are for higher concentrations, people have said it only stays on the skin for a very brief period, no longer than a few minutes. I have a 3% acid wash and I'm not sure if this would be the same duration as the others? On the box, the only instructions it gives is, "Use twice a day, AM and PM." So I'm also curious and confused, for how many daily uses and how often between uses, or is everyday safe.