Silver cleaner down the drain- sulphur smell- what to do?

I spilled a little silver cleaner down the drain a few months ago. It still has a chemical/sulphur smell. I've tried baking soda/vinegar, and we use the sink several times each day. What should I do? Not all drains have this smell- only one. I'm guessing the metal in the drain is just reacting still? Do I still need to check my water heater?!