does it also work on existing clogged pores/blackheads? how long before they go away? is it ok to just use bp not whole regimen for this?
Yes. It should absolutely help hasten the removal of clogged pores and existing blackheads. For some people it is literally overnight that they see a change. For others it can take a few days. For super stubborn cases, it may take longer. I always suggest people follow The Regimen exactly as outlined until they are completely clear and happy with their skin. At that point you can try other stuff like only using the bp and not the whole regimen.
Also, once your skin is accustomed to bp, try adding in 10% glycolic acid in the form of either Acne.org AHA+ (highly recommended) or Alpha Hydrox Enhanced Lotion (will also do the trick but not quite as well). These 2 glycolic acid treatments will help quicken turnover of your skin and prevent future clogs. The combo of The Regimen plus glycolic acid will have your skin looking insanely good. Try it out.