Being on the regimen means that your only use the products Dan recommends - a gentle cleanser, 2.5% BP and moisturiser. Jojoba oil and AHA+ can also be incorporated to reduce dryness/flakiness.

So I would say no to this question. If you are to use alternative products, stick to the ones that are recommended.

As Lewis said, it's best to follow the recommendations for choosing products. Dan has a list of things to look for as far as ingredients go, and some recommended products that we have personally used and know will work. Read here: http://www.acne.org/supplies-guide.inc.html