A step or turn in an area (route, cave, whatever) with wild pokemon will advance the RNG by one. The 128 step counter applies everywhere, however. So basically the best way to advance the RNG in the wild is simply turning, rather than taking steps.
Also, Spiritomb is method J for those who were discussing it. It's pretty much the same as Rotom or any other stationary legend.
Ok thanks.
EDIT: Forgot to calculate the monster frame. Just spent an hour biking around for no reason! Ahh...
So the monster frame is 1. 2,140(target frame) - 1(monster frame) - 0(wandering pokemon) = 2,139. So I should be able to flip my journal twice(page with captured pokemon) to advance by 4, then walk 54,656 steps, right?