If cleaning a barrel is bad, why do benchrest shooters clean their barrels every 10 rounds or so?? Educate the unwashed please...
They have the time.
I've spent weekends competing, firing 300 rounds for points. If someone played a joke, and cleaned another shooter's barrel when he wasn't looking, the guy that did the cleaning could expect a broken nose over it, possibly.
Point being, clean barrels don't keep shooting well for very long. There's a clean zero, a clean POI for a certain number of shots, then it changes and stabilizes for X number of shots. Talking to Judd (BR shooter) his barrels, and his gunsmith's machining technique is exactly the same as mine. Judd is running a BR stock, and a way different action, that shaves another 1/8 MOA+ off what mine can do. But he's got the time to clean between a relays, I do not.
The barrel crosses a hump getting fouled in, the holds true for a certain number of rounds. That number is load, bullet, powder charge, barrel length specific, and it varies rifle to rifle. The barrel I have that likes to be cleaned the most often is a 7mm-08 A.I. on a button rifled Tikka barrel. It starts to open up around 50 rounds. But I have several cut rifled barrels that keep shooting exactly where I tell them for 200 to 400 rounds, depending on what I listed above.