I'm not an engineer, but my gut tells me you either want a clean barrel, or a dirty one. I can see both arguments. I've always read that the value of a fouled barrel is that the fouling will "even out" the rough surfaces in the barrel. I know that from a precision engineering standpoint, this probably makes some people's skin crawl, but from a practical standpoint it makes a lot of sense to me.

I know I didn't see the best accuracy from any of my factory Savage barrels until they had at least 50 rounds through them and in two cases, nearly 200 rounds. I was ready to give up on a barrel once that would do no better than 1.25" for the first year I owned it. But after about 200 rounds, it would do no worse than an inch and often much better.