I think everybody can agree on cleaning the barrel thoroughly before ever firing the gun. The grease the factory put in there was to prevent rust, not to make it shoot better. Any dust, grit, cardboard fibers, etc that stuck to the grease should be removed. It may take a while before clean patches start coming out, so take your time.
The actual shooting is more debateable. Some like to clean after every shot at first, then clean every five shots, etc. Some shooters might just take it to the range and shoot a box or two of ammo.
Mitch.