Crashdance, if the lane divider has a rubber post you want to nudge forward so the ball goes off the post and out of that area. If you are forward nudging but the ball is still bouncing around the inlane/outlane, you aren't nudging hard enough.

If there's no rubber, like on a toughened up tourney game, you have to nudge a bit harder.

If the ball is already settling in the in/out lane area, then side to side is needed, but ideally you don't want to put yourself in that position to begin with because no matter how good you are it's tough to reliably recover the ball.

On many EMs there is just a simple wire divider. Unfortunately, they are very good at dissipating force and a forward nudge is often useless. On these you need to anticipate the balls travel and slide the game left/right as needed to get the ball into the inlane.