Okay, are we arguing about how PBlaster smells, whether it is a good penetrant...or are we answering the original question?
I have PBlaster and use a fair bit of it...on rusted fasteners. Works great for me.
I have never had a reason to use it on a gun, and unless I find that Rossi I threw in a lake back in 1984 (old story, well documented, no illegal activity) I won't be using it on any guns in the future.