you can Import your model to Blender, go into edit mode and hit Alt-J now you can click on smooth Vertex. If you want more smoothness on a rather low Obj just subdivide and smooth it again, depending on your mesh if it falls apart when smoothing you will need to "remove doubles" first. after this step just save a new Obj and Import it into poser you now should have a neat and smooth Prop . Note when Hitting Alt-J set the option to Compare UVs avoiding it to get messed up.

This would be an easy Free and fast Fix for your Issues