If you don't want to loose ceiling height, you will need to remove the celing covering to gain access to the floor joist cavities.
A product we've had great sucess with is Roxul (http://www.roxul.com ... read more
I must confess to never having seen that application.
I am not sure the finish would look good or even hold up over the long term. I would also be worried about the potential vapor retarder ... read more