I am not a fan of Berber carpeting. I have never had any luck with cleaning it. It's so tightly woven that it is impossible to really get in and clean the fibers. In our house, it is impossible to keep the carpets clean so being able to clean them is a necessity.
I found this homemade concoction at Glamour.com that is supposed to be the best. I have decided to put it to the test. (I have since seen this concoction mentioned many other places, seems like it is everywhere...)
The concoction calls for 1 part dawn dish soap to 2 parts hydrogen peroxide. I did no such measuring. All I can say it that I had more peroxide than dish soap.
I think it cleaned very well. It cleaned better than any other cleaners that I have tried. I'm still not a fan of Berber. Since I was doing just a general cleaning of the carpet and not direct stains, it was difficult to tell in pictures so I did not include any. You will have to test it out for yourself. We have Cream/White (I know, I know, I didn't choose it.) carpeting. If trying this concoction on a color, I would suggest testing it in an inconspicuous area first.
It cleaned so well that I decided to use it on the whole floor with my Bissell carpet scrubber. For this I used approximately 1 part carpet cleaner (still have some and I won't let it go to waste) and 3 parts peroxide in the cleaner solution compartment. Worked like a charm.