Slide baiting basically works like this:
Cast out a grip sinker and the stopper ring that comes with the slide and make sure it’s anchored well (no bait attached).
Clip on your bait to the main line with the slide.
Slide down the bait to the stopper ring.
Example video on how to slide sucessful: Watch on Youtube.
There is also a great article about slide baiting from Reefman in South Africa: Download from Dropbox.
This method is great for getting big baits into the strike zone for big fish like Sharks.