First the bragging … I earned my Grand Master in Practical Pistol Competition in late 1995 or early 1996, who remembers dates … Expert in IDPA in three divisions in 2013 … B class USPSA Limited about the same time … held down first place nationally through most of last year in ABRA Factory class, shooting a nearly “stock out of the box” 10/22 LVT …
I’m one of the most resistant people you could ever find when it comes to cleaning a gun, usually just ripping the bore snake through my semiauto pistol until the feed ramp looks good, then lock it in the safe until the next match.
BUT … our club president introduced me to reality in .22 rifle barrels when he suggested that I clean my match barrel as usual, then soak a new bore brush in solvent, run it in and out a few times, then send a fresh patch down the bore. Amazing how much crud that will flush out, and how much better (kind of like when it was new) that barrel suddenly shoots.
So … in IDPA and USPSA matches where your 9mm or what have you is engaging targets at speed and not usually past 20 yards, just give it “a lick and a promise”. But if you want precision accuracy, work on that barrel until you can’t find a bit of residue from anything in it.
YMMV as the acronymists like to say. But give it a try, if you care.