You need to make a solid, watertight mesh of the figure anyway. I would do this with ZBrush's dynamesh, Blender has some similar working tools too. I think the voxel remesh feature would work. Another way create a solid hair block would be to surround the hair with a closed mesh (a ball for example), use a shrinkwrap modifier in Blender to roughly bring it into shape and then use the sculpting tools to refine the surface.

Things which I find harder to do is to transfer the data of normal maps back to the model. Low Poly looks crap when 3d-Printed, and the usual cheats for rendering do not work very well.

A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori.