What's the most effective home acne treatment?

Benzoyl peroxide: This is the best that's over the counter but not nearly so helpful as something as simple as topical Clindamycin with or without BP or a retinoic acid derivative -- i'll use the latter if there are many blackheads. If your acne is worse, a systemic antibiotic can help, and a dermatologist can use the big guns. You shouldn't need to rely on a home remedy even in our loony health care system.