Have never dipped tobacco, but I can do the motion you're describing, if I pinch my thumb and middle finger together so that my index finger hits them it makes a pretty solid thwack sound

Can only do it with my right hand though, my left index finger just doesn't go limp enough or have the same range of motion or something

Takes a lot of practice to let the index finger go limp while gripping with the other two.

And also not grip it tight enough it pops the lid off and contaminates the entire pizza topping table with Copenhagen™