No problems cleaning the brake. Mine gets caked on carbon deposits down in the threads. Remove the brake, wet the barrel threads with a wetted solvent patch, and then I scrub the threads with a 45 cal bronze brush. A tooth brush isn't stiff enough. On mine the internal brake threads stay clean but the carbon sticks to the barrel threads.
If you mean for hunting, i'd not hunt with a muzzle Brake. It WILL damage your ears. Get a thread protector that screws on the threads after the brake is remove. You will not notice any recoil when shooting at game without the brake...but you will notice ear damage when hunting with a brake.
I always clean the bore and like BD1 said clean oil and wipe clear. Nothing like a few days in raining PA deer season to start rust on a gun.
A few years ago I went to a rifle range with a couple of
guys that I work with to sight in a new varmint rifle.
A guy about 4 or 5 benches down cut loose with a braked
300 or 7mm the range has a metal roof and it really startled
Cleaning the break will not effect accuracy, cleaning the barrel may or may not, why take the chance, a fouled barrel will always shoot where you aim. If you haven't tried shooting with a clean barrel to check point of imapact I would leave it dirty. Some of mine shoot OK with a clean barrel and some don't. As far as a thread protector you'll need to go to a gunsmith, he'll fit it to your barrel. Shooting without hearing protection is dumb, we all do it from time to time and in a hunting situation it's still a bad idea, i understand the argument, hear the deer and put up with the muzzle blast, wear protection and don't hear the deer. I would never ever hunt with a muzzle break and not wear hearing protection. There are a lot of good electronic muffs which will give you the best of both worlds, hear the deer and eliminate muzzle blast