I like the Neutrogena Body Scrub or the Body Wash. It's comes in a large container. For me, I'm getting ready to start accutane because I have had no luck with everything else. However, these washes have done pretty well for my back and chest. Good luck.
Clinique make a range for blemish-prone skin including a chest and back spray. If your acne increases in severity a topical lotion would be impractical to apply on large areas. Rather, an oral antibiotic such as Lymecycline or erythromycin might be indicated. Loiloi x
I use the Neutrogena body scrub and a loofa and it helps. I have also used Nature's Cure before. they have treatments for face and then some specific for backs. it is a pill you chew and a spray but I have found luck with using the body wash and just the spray. It has not completly cleared my back but it does help a lot.