Dry Chlorine Bleach
Unlike it's liquid cousin does not obviously splatter or splash, so dosing is easier with less chances of getting the stuff where it shouldn't.
Not sure, and others more in the know can chime in, but IIRC the dry version of chlorine bleaches rinses from fabrics easier than the liquid and is slighly less aggressive.
Remember speaking with a Miele tech years ago about that brand's ban on LCB in their washers, and was told that occasional use of the dry version shouldn't be a problem.
Finally think the dry version of chlorine bleach is a bit more stable and has a longer shelf life (with proper storage), than liquid.