Hi kschaer,
Rhino is great for almost everything, but cleaning up digitized data of the quality you´ve posted is something you never should try to do in Rhino. The outcome of the nextengine scanner is really bad, most problematic are the missing parts. A watertight mesh is attached below, because of the missing parts in the source mesh, some areas had to be filled in using various scientific algorithms.
If you would like to make changes, add details or further optimize this mesh, take a look at sculpting software like sculptris or meshmixer. Both are freely available for the mac and can import the obj file format. Rhino can export using obj.
handPointing_cg.3dm (4.7 MB)
c.