No, it's not an in-game team. It's for random battles online. Nothing serious. I don't do serious.
The Choice Scarf is there because Salazzle has literally no coverage moves other than what I've given it. Toxic is a situational move; Salazzle scares out a lot of Steel Types, and on the other side of the coin, lots of Steel Types switch in to try to wall Sludge Wave. It's a perfect use of Corrosion, and I can just switch out after.
Lastly, I did say in the post I don't have the rest of my team yet.
You don't need any additional coverage moves. You could add a Hidden Power of choice, probably grass for Rock + Water types, but Nasty Plot would be the best move for the 4th slot. It powers up Salazzle's already high sp attack turning it into a good sweeper. Equip a Life Orb for more power.
And yes I saw in your post where you said that you don't have the rest of your team but that doesn't change the fact that it makes your squad hard to properly rate. Even if you don't have them yet maybe specify a few mons that you are considering using to help out a bit.