There are some cleaners that are mildly abrasive that some use to polish new bores (names escape me). I have never used them but others have and post here. Maybe some one will with that data.
Flitz is one that is probably harmless but I've never used it. In my opinion, bullets going down the bore over powder ash is abrasive enough. If you clean the barrel REALLY well after each 10 to 20 rounds over the first 100 or 200 rounds, barrels smooth out and do become easier to clean.
My favorite cleaners are:
Patchout
Wipeout
Prolix
Barnes CR-10
Shooter's Choice
Butche's Bore Shine
I use them all in about that order of preference. The stuff from Hoppe's and Remington is pretty worthless.