The basic problem with using it as a prop, you lose any morphing capacity associated with the object. If you are only interested in original static pose of the piece, then converting it to a prop won't be an issue. But if you want to retain any ability to change the style/pose, refit the hair and parent to the figure. I have come across several old tutorials which detailed the conversion process. And I have come across morph fits which included multiple base figures as parameter dials. I would imagine it would not be too difficult to spawn a morph fit dial in Poser and save out the modified hairpiece into the Library for future use.