If you touch with the back of your hand, you might get shocked but when/if your hand locks up it won't grab on to anything. The electricity itself isn't holding you, it just interferes with the way your brain talks to your muscles and you end up holding yourself.

I think you have that backwards. AC causes muscle contractions. If DC did, you wouldn't see videos of people locked on to things that have become electrified, because the power from the plant is AC. That's why Edison electrocuted an elephant.