Proactive, iirc, is essentially salicylic acid and
benzoyl peroxide. You could try to dupe using + "natural" salicylic acid aka willowbark extract, but you want to use an item that has enough of it to matter. Instead of BP, you could try diluted tea tree oil, since it also kills germs on the skin like BP does. A general routine would have a basic cleanser, a SA/willowbark treatment, and ...