Brute force isn't necessary.
I use Shooter's Choice bore cleaner.
Other people like WD-40, Ed's Red, Hoppie's, etc.
The trick is to get the bore coated with a solvent, give it about 5 - 10 minutes to do it's chemistry thing and then use a cleaning patch to push the loosened fouling out. Continue with the patches until you get a clean one (or reasonably so) and you're done. Choke tubes sometimes require special attention, i.e., removal and separate soaking and scrubbing. But I only do that occasionally. Usually the procedure I described above is sufficient.
HTH