yanno, i used to say "excuse me, may I get past you" to such bovines (and to dirigibles hovering in doorways, et omnia generis alia)... but now I am more likely to say "Get the [expletive] out of my way, NOW."
their lack of manners has led to a reduction in my manners. it's a vicious cycle.
I've observed that women are quicker to say "Excuse me" than are men, even if they are passing by in the aisle of a store. There is no reason to apologize and I wish they wouldn't.