Are these acne treatment medications (benzaclin (clindamycin and benzoyl peroxide) gel and differin cream 0.1%) effective?

Acne. Both can be effective, although through different actions. Benzaclin (clindamycin and benzoyl peroxide) is more effective with acne causing bacteria. Differing is a retinoid. Uses in conjunction, they can be very effective. But, it's all trial and error.