It could likely be because you're not washing away the concealer thoroughly. Can you try not wearing concealer?

I agree with the above poster. If you're going to go caveman then you need not use ANYTHING on your skin as everything besides water will leave a residue on the skin. Keep in mind also that if you were using chemicals to control your acne, withdrawl can reek havoc on your skin for months. Lastly, cavement will only clear up your acne if your acne is primarily caused by over use of products or irritation. If food, hormones or other factors are primarily the driving force of your acne, the caveman won't help much