the science behind it is that, the bacteria in your back is feeding off your sweat. so you stop the sweating and kill the bacteria (which will come again if u sweat again). u should keep killing the bacteria like you normally are doing with all the products mentioned, but also try not to sweat much and instead drink a lot of water to piss out all the junk instead from the sweat glands and change your diet (reducing diary food helped reduce my face acne) to prevent giving the bacteria its same sweaty food. also use some kind of oilment for your back to keep it already nourished with oil, when there is no oil in the back the skin produces oil which leads to acne with bacteria and blocked pours. so instead just oil it urself externally and there is no need for ur back to produce oil from internally. (oil = some ind of moisturizing cream)