[Acne] Need some opinions on bacne treatments

I started getting mild bacne around Christmas time, I tried using Head and Shoulders as a scrub and applying a small amount on my back at night and had good results for a while. I kind of toned it down a bit and my back was looking good

Recently broke out more on my traps/back of my shoulders. I was thinking of trying something a little different.

I have head and shoulders I can use as a scrub, or a salicylic acid 2% body wash scrub. I also have .05 tretinoin cream, should I use this?

My back doesnt break out too bad all the time, the red marks just take FOREVER to go away so it looks worse than it is.

I havent read much about using tretinoin cream on the back, is this ok? is it a good option? thanks