I'm a pretty serious 3P Olympic small bore shooter, and am not particularly anal about cleaning. When the rifle needs it, the scores will drop off. Long as the 10's keep flowing, why mess with success? Even when I was in college before a competition, if we'd clean the rifles we would burn at least 100-200 rounds through the barrels after cleaning to get the barrels to settle down again.
Cleaning during a competition, at least for 3P, is madness. You would never do that. The bore guides you mentioned, at least for a 54 Action Anschutz is to keep the solvent out of the trigger group as parts of them are epoxied in place and some small parts are plastic. In my time behind and Anschutz, I think I can count the number of times I've felt the need to use a brass brush on one hand. With match ammo, the barrels simply don't accumulate that much crud. I personally never gave much thought to how much my fellow competitors were cleaning or how anal they were about it. It's all in the scores. Do what works for you. What worked for me was a very simple and very light cleaning regimen. I can also attest to many shooters who were much better than met at the time who saw a lot of success with the very light cleaning regimen I described.
The ones I do know clean their rifles after every competition are Biathletes, but that's more about removing water from the snow. I imagine they probably run a patch with some oil after every race to drive the water out. Ill let you know next year when I'm hopefully a competent enough skier