Probably not... But since it doesn't really harm the animal by way of toxicity, and I like to make sure it is effective, I have done it that way forever.
Plus, I have a gallon jug of the stuff. I like the pretty blue
Edit: Also, its not going on the snake or in the snake themselves at all, just inanimate objects such as tubs and waterdishes, which are all dry before use, which is why I feel comfortable with the 1:10 mixture instead of the one ounce to gallon rule.