Actually, Snuffy's right. The stuff that gets embedded in the fibers tears stuff up.
Thing is, we're not really talking about rifles that are all that accurate to start with, so you're probably not going to notice anything. Military rifles are built more with reliability than accuracy in mind.
I think it'd be okay to get general crud out but I'd just run it through once. Ain't gonna be all that much cleaner with a few times.
There's really no substitute for a bore guide and good one piece rod, with the proper solvent.