Mounting Man, weather conditions have a lot to do with what you can get away with. Down here in Louisiana humidity I want to clean a fouled bore within 24 hours regardless of whether the fouling is real black powder, Triple Seven, or Pyrodex. In a low humidity situation you could probably go a bit longer so long as you monitor the condition of the bore.

You might give consideration to hunting with a clean bore. It's a bit tedious to find out if the clean bore/first shot from a barrel is consistent. But I find it worth the trouble. You have to shoot at least three shots (five is better) at the same target with each shot from a fully clean, dry, and cold bore. After each clean bore shot, shoot a second shot with the fouled bore on a different target, with all second shots on the same target.

If the clean bore shots form a decent group, sight the gun in for that group. The target from the second shot/fouled bore shots will tell you what kind of Kentucky Windage is needed (if any) in the event a second hunting shot on a fouled bore is necessary.