Just taking a look at the product, it is a very high polycount item which would mean that trying to make it cooperate with the morph brush will take some time and effort.  Importing it into a modelling program might be the only option to achieve an upside down look.  However, manipulation might drastically change the vertex count and order; this would render the changes as a morph target useless, in which case, it may need to be converted to a one-time hair prop.