Isn't there a bracha for saying over non-kosher food if one is forced to eat it to sustain life? The one I can actually find with a google search, bore nefashot rabbot, was used during the Shoah, and it would be trivializing it to use it over a cheeseburger one just wanted to have for the pleasure of it. I get the sense that saying it over non-kosher food neither rendered the food kosher nor made matters worse. That it allowed Jews of that time to survive with their dignity and faith intact, I think, means one should probably not be quite so flippant about it.

Likewise, if an unmarried woman is going to be having sex, but needs to maintain some kind of connection to G-d and to her own sense of the right thing to do, it seems to me like doing the mikvah is still a blessing.