This stuff really works! I have sensitive, oily, acne-prone skin and I get really clogged pores and whiteheads on my T-zone. After one use, this cleanser dried up a huge cystic pimple on my chin, cleared small pimples on my forehead, closed up the huge pores on and around my nose, and helped get rid of most of my whiteheads. The label says that "25 times more acne medicine remains on the skin after rinsing" and it seems to be true because most salicylic acid cleanser don't do squat for my stubborn whiteheads and blackheads.
It is drying, as some other reviewers mentioned, but if I use this only 1-2x a week (at night), it doesn't make my skin itchy or flaky. I think it's best to use this as a weekly treatment than a daily cleanser. Otherwise, it will dry your skin out too much and/or make you break out worse because it disrupts the natural barrier of your skin. If you have sensitive skin, maybe use it just once a week; if you have oily, resistant skin you can probably use it twice a week.
The other cleanser I use on a daily basis is L'Oreal Revitalift Radiant Smoothing Cream Cleanser, which also has salicylic acid but a lesser amount and it's not as drying. If you have stubborn acne, I would definitely recommend trying this Oxy cleanser but don't use it daily unless you're sure your skin can tolerate it. Hope this helps!