T7 is less corrosive than Pyrodex as well.
I hunted deer with my muzzleloader a month ago. Having never used T7 I wanted to know how long I could wait until cleaning. I asked here and everyone said it had to be cleaned immediately.
I didn't want to clean it,just to re-foul it before hunting the following weekend. I bucked the system and never did clean it. Its been a month now and there is still no sign of corrosion. Back when I shot Pyrodex there would be corrosion in just a day or two.