I'd either jut use Pyrodex R-S or Goex FFF...

They are both fairly cheap, easy to clean, no crud ring and very consistant...

As far as corrosion, as long as you clean and oil you muzzleloader, no problem...
If you don't want to take the time to do this properly, maybe you should be using a cartridge gun...

Actually, I have buddies that are too dang lazy to clean their cartridge guns as well...