Well the main focus of the regimen (aside from the BP) is to reduce irritation. The PMD is the epitome of irritation if used incorrectly - it removes a full layer of skin which is going to reveal highly sensitive new layer of skin that is underneath.

If you are dead-set on using the PMD, wait until you're fully clear and adjusted to the BP (no flaking and no redness). I would advise you not to though, there are much better forms of exfoliation out there like AHA.

Imagine taking sandpaper and then rubbing it round on your face in fast circular motions. That's what the PMD essentially is, a small sander. I personally don't think us acne-prone people can get away with that kind of irritation.

I agree with LewisS. Although, I began the regimen recently and im going to wait to try out the PMD.

That is what caught my eye. She used it and looks completely flawless. Just make sure you understand there is still the risk of irritation!