Unlike your face, body acne tends to need something quite strong, or drying to get rid of the acne because the skin is thicker and less sensitive. I recommend using products high in benzoyl peroxide.

I have been using the Panoxyl 10% Benzoyl Peroxide Foaming Wash and it's been working great to dry out my chest and back acne. I use a body scrub brush and then apply this Panoxyl Wash and leave it on for about 2-3 minutes then wash it off in the shower. When I go to bed I apply a 10% benzoyl peroxide cream to my back, chest, and shoulders. I do this every single day.

I'll admit, my back and chest have been getting quite dry because of the benzoyl peroxide but it's getting rid of the acne so it's worth it.

Good luck!