it depends on a lot of things, but mainly stress/hormonal imbalance and also what you are putting into your body (foods, lack of vitamins) will determine break outs more than your skin being "not clean".

i take a herbal supplement and that has cleared up my (really bad) cystic acne. i went on a variety of pills for a while, and they were great, but the side effects eventually got to me (morning sickness). but i am particularly sensitive to that.

i would recommend talking to your GP. they might be able to give you a topical treatment that will clear your skin up, and help implement longer lasting change. a dermatologist would be ideal, but your GP would be able to tell you if it's worth the visit.