According to the real experts, there is no question! ALL vinyl records should be cleaned, even new ones. New records will have the residue of mold release compounds (old ones may, as well, if they've never been properly cleaned before) that should be removed, along with any other microscopic and non-microscopic detritus that may be present after pressing. There are many methods of doing this effectively. Of course, proper care, handling and storage of records are very important, as well (e.g. quality anti-static sleeves). After cleaning, you might want to consider using a product called "LAST" record preservative. Google the LAST Factory and see what you think. However, don't take my word for it. Read this:
Precision Aqueous Cleaning of Vinyl Records-2nd Edition - The Vinyl Press
Not an easy read but as informative a source on this subject as you will ever come across. You might also want to read what the Library of Congress has to say on this, as well.
Precision Aqueous Cleaning of Vinyl Records-2nd Edition - The Vinyl Press
Not an easy read but as informative a source on this subject as you will ever come across. You might also want to read what the Library of Congress has to say on this, as well.