Since i was a child i was told that current has pushing or pulling effect. However, i never got a dc shock and i don't remember ac shock (i got it very long before). The day before yesterday, an experienced electrician told me that dc has pulling effect ( most of the batteries supply only 12V it's not so much to worry but if supplied with very high voltage it is very deadly comparison to ac and) and ac has pushing effect. Logically i can't find any explanations. electricity is just flow of charge, and in our body, we have more electrons than protons (from C-14 decay) but still very less than enough to give shock or pushing or pulling effect.
I suppose by "pushing" and "pulling" is meant to describe what happens with accidental electric shock. What happens when one touches a live wire the body provides a conduit to ground and a current is set up. This article in Wikipedia explains the physiology:
DC tends to cause continuous muscular contractions that make the victim hold on to a live conductor, thereby increasing the risk of deep tissue burns.
So there is a reason for the rumor.