Farmer's Sneeze

Any idea as to the origin/meaning of this one? I read it in a comic strip where it was jokingly a part of an exercise regiment: "Do a farmer's sneeze on a big dork's pickup truck tire".

A farmer's sneeze is a way to evacuate one's nostrils. Using your forefinger, press nostril to mate and blow. The first page of John Steinbeck's The Red Pony (The Gift) has a wonderful description of this feat.