I wish I could answer your questions, EpiRider. But I've never used the powder'd stuff either. All the products are supposed to promote clot formation, which I guess could get aggressive and occlude the entire vessel (the article I cited mentions that they were patent in all subjects initially). But you're right, it may occlude distally, or even proximal if it got into a vein, which I assume is how the pigs got the PE's.
JohnN, no personal experience with that brand, but it seems (to my mind, anyway), that an impregnated bandage would work better than the powder.
As a somewhat puzzling aside, our Navy Exchange is still selling the powder'd stuff on their shelves for personal use. Wierd, huh?