Did you try suggesting to them that they stop blocking the submission with their face? If they did that, they may find it a lot less painful (or a lot more or a choking hazard, but whatever).
Its your shin, not the bottom of your foot. You could however go loco on them and put your dirty foot on their face and make them smell it, or taste it if their mouth is open. Then we are talking dirty.
I aggree that a Tap is a Tap. If its not written in the book then it should be legal right?
Took a guys back once and went for a rear naked Choke, but hekept his chin down and placed a hand on my arm. my wrist bone ended up sitting just between his chin and lower teeth and I just pulled it tight and he tapped.
Doesnt matter if it looks nice or looks ugly, a tap is a tap.
Balls in your face in just north south, but a foot near your face is bad? lol. I pulled a gogo today, used it to sweep ala/asylum style, then finished the gogo from mount. the only guys that dont like the gogo are un flexible dude that havent executed one. Facial any one?