The homeowner is more than likely talking about MR board(moisture resistant drywall)which is used to minimize moisture problems on walls and ceilings,its made to tolerate high humidity and low moisture.Yes it will work,however 1.make sure all insulation behind the "blue board" is unfaced.The mr board provides a vapor barrier,kraft insulation will make a double barrier-a big no-no. 2.Do not use it in an area where it will have frequent contact w/water-if your gonna use it on lower portion of the tub wall tile it w/adhesive or use a tub surround.It is an excellent idea for bathrooms,but if your gonna use it on ceiling you have to use 5/8 on 16" centers or 1/2 on 12" centers.You can buy it at most building supply yards,even Home Depot-but they only have 8' sheets(at least where I live).It is a little more pricy,around 2.25 a sheet more for an 8' sheet around here.

Unfortunatly
the home owner mentioned that this is a new product made of a plaster and fiberglass mixture that is diferent than the standerd green board that I've used in the past . The guy at 84 lumber did tell me that it is made by USG but cant seem to locate any other info.

I've never heard of it or used it.hmmm..did you try USG's website www.usg.com ?