That should be for you to experiment with, but I can give you some basic idea.

You can use the Dunk to grab people in the air and dunk them, if there are platforms under that opponent will just fly through them.

You need good timing, and know the hitboxes.

You need to really experiment with it.

The Basic combo for the dunk is a up-tilt up-air (aka the dunk part 1).
this Combo is very basic, but if performed correctly, it will make your opponent either fly out, or need to get back onto the stage.
There are some characters who are going to have a easier time surviving your dunkster roll, like orcane or maypul. (both under certain circumstances)

Just Keep on going, don't give up on dunking.

Just Dunk till they want to nerf etalus, AND THEN DUNK SOME MORE.