I just took a leak in my dogs water bowl
Why did you do that to your dog's drinking water?
Someone told me that if you put salt in your dog's water bowl its food will taste better.
It's essential to use a toilet to separate and flush away human waste because exposure causes diseases. You are not living up to your responsibility to your pet by making them drink dirty water.
Umm, okay. I'm finding the salt to add to the bowl right now, and I'll wash it right away as well.
It's good that you have decided not to pee in your dog's bowl, and that you are going to provide it with clean water from now on.  I would advise against adding salt, as well, just give the dog clean water.  You don't know if the dog actually likes the taste of salt, and it already gets enough minerals from its food.