I just got this one the other day. No do not boil the water slow simmer cook for a few hr's is how I do it. After you put it in the fridge the water will settle under the butter just drain that off.
http://www.amazon.com/gp/product/B00006IUXW/ref=oh_details_o00_s00_i02
http://www.amazon.com/gp/product/B00006IUXW/ref=oh_details_o00_s00_i02