There is a lot of good advice about acne at acne.org. Personally I suspect that for many people a combination of things is necessary (identifying and, if possible, eliminating the cause of the acne; what to put on skin; etc).
For many years I used benzoyl peroxide wash in the morning to wash my skin and glycolic acid gel at night, and that helped a lot too.
I also have a Zeno and it seems to help with the normal pimples that grow outwards instead of inwards. (I didn't feel like it helped with the cystic acne that grows inwards, but it is worth trying)