It does have potassium chlorate in it, but no sulphur. I've run 5 lbs through this one barrel now, without any evidence of corrosion or fouling. Chlorates will attract moisture and I probably wouldn't recommend leaving a charge in for weeks on end.
Of course, I flood the barrel with water after each shooting day, wipe with ballistol, dry and finish with WD 40. Chlorates are water soluble, so water is the perfect cleaning medium.
Considering the difficulty and legal problems with buying Goex type powders, this is working for me at 2/3 less cost.