I slide with a .8mm to 1mm mono hook snood so the sharks that pick me up "self release"..I think there are more sharks and rays in SA than cob as maybe every fourth livie will be a cob on average, with more bycatch than the intended target. I've picked up more than enough monster sharks putting a livebait out than I can remember, at night, that I dont want to be landing on my own or trying to drag onto the rocks LOL..To answer the OP's question, yup many slide for edibles.
Drones have made sliding less popular and at the moment in places like false bay and such the cob are getting hammered by those who used to slide and now are going recromercial trying to pay their drones off..but ja sliding for edibles very much alive. Guys slide for garrick also and I learnt to catch them on a livebait under a balloon but these days I get all my garrick on plug or spoon, they are just easy if not more so to get to hit a lure and it is way more fun, this season has been decent, 10-20 so far, lost count..Cob, I've caught almost as many on spoon this season than on livebait..
But one of my favorite pastimes is to sit on deckchair on a still night on a safe beach, when the conditions are right, with a shad or mullet slid out and a glowstick on the rod in pension pipe, and a beer, a few prerolls and some snacks and my dogs...and wait for that pick-up, real de-stressing fishing! When you have a livebait out you know most likely a bite will at least be a proper fish, shark or not, barbel aside.