is it necessary to add oil in the 2 holes on the side of the bolt carrier group?
CLP works, it has a dual role of solvent and lubricant. It does not clean like a good solvent, does not lube like a good quality lubricant. But is seems to work, there are better lubricants, and greases.
I use Shooter’s Choice products FP-10 and Shooter’s Choice grease.