After analyzing the search results, here are some of the best body washes for acne on the back and chest, along with their positive and negative aspects, and ingredients:

1. Neutrogena Body Clear Acne Treatment Body Wash with 2% Salicylic Acid: This body wash is designed for acne-prone skin and contains 2% salicylic acid to help treat and prevent acne breakouts. It also has grapefruit extract and vitamin C to unclog congested pores while removing dirt and impurities without over-drying skin. The product is dermatologist-recommended and comes in an 8.5-fluid ounce bottle. Positive reviews mention that it is effective in clearing up body acne, while negative reviews mention that it can be drying for some people.

2. Proactiv Deep Cleansing Acne Body Wash: This body wash contains 2% salicylic acid and exfoliating beads to unclog pores and prevent breakouts. It also has aloe vera, shea butter, and glycolic acid to balance the cleansing agents while hydrating and moisturizing the skin. Positive reviews mention that it is effective in clearing up back acne and keratosis pilaris, while negative reviews mention that it can be irritating for some people with sensitive skin.

3. Exposed Skin Care Body Wash: This body wash is specially formulated to target acne on the back, chest, and surrounding areas. It contains salicylic acid and tea tree oil to exfoliate and unclog pores, while also hydrating and moisturizing the skin. Positive reviews mention that it is effective in clearing up body acne without drying out the skin, while negative reviews mention that it can be expensive compared to other body washes.

4. Tutta La Pelle Acne Wash: This foaming wash contains 2% salicylic acid and tea tree oil to help prevent breakouts and soothe irritated skin. It is also free of parabens, sulfates, and fragrances, making it suitable for sensitive skin. Positive reviews mention that it is gentle and effective in clearing up body acne, while negative reviews mention that it can be drying for some people.

5. PanOxyl Acne Foaming Wash: This foaming wash contains 10% benzoyl peroxide to help treat and prevent acne breakouts. It is also free of parabens, sulfates, and fragrances, making it suitable for sensitive skin. Positive reviews mention that it is effective in clearing up body acne, while negative reviews mention that it can be drying and irritating for some people.

6. Vanicream Gentle Body Wash: This gentle body wash is free of fragrances, dyes, and sulfates, making it suitable for sensitive skin. It contains glycerin and ceramides to hydrate and moisturize the skin, while also cleansing it. Positive reviews mention that it is gentle and effective in clearing up body acne without drying out the skin, while negative reviews mention that it may not be strong enough for severe acne.

When choosing a body wash for acne on the back and chest, it is important to consider the active ingredients, as well as any potential irritants or allergens. It is also important to follow the instructions carefully and use the product consistently for best results.