Laundry question, please help!

[rooster2012]

Okay, so I'm not new to cloth diapering and have been using a variety if products (synthetics and natural - mostly bamboo and hemp). I just decided to venture into the world of cotton and now have a dozen imagine bamboo prefolds (I realize these ate bamboo and cotton) and workhorse fitteds. The GMD instructions say absolutely no RnG. I've alternating BG detergent and RnG since I started cloth diapering. Why can't I use RnG on cotton? Can I use the BG detergent? Help!