What will happen if you use a stainless spoon to stir salt into water?

Oh, dude, if you use a stainless spoon to stir salt into water, nothing too exciting will happen. Stainless steel is pretty resistant to corrosion, so your spoon will be just fine. It's not like the spoon will suddenly turn into a magical wand or anything, it'll just help you mix that salty water like a boss.