Yes I have.
It is very hard to do and does not worth a damn.
Have been wearing a Sharpened Dog Tag for 22 Years and have yet to have a self-inflicted wound with it. The Caveat to that is that my tags are taped together for no rattle tattle wear.
$36!! Jesus H.
To clarify. Are you wearing a sharpened aluminum-issue dog tag or are you wearing a purpose-built knife like in the pictures above?
I am wearing a GI Dog Tag w/ an edge on it. I placed the sharpened edge on it back in 1990. I mainly wear it out of habit as much as any other reason. Cause you are not going to do a whole hell of a lot with it. It was truly a last ditch my buttocks are in the fire tool.
I do also have a Purpose built one (The Original Dog Tag Knife) as well in my boot laces with Red Tag in the laces of the opposite boot.