I'll probably rinse just in case. Are you applying the ox pretty heavily?
2lbs to 5gal. What you have to remember about the ox is that it's reacting with the concrete and effectively neutralizing itself. That's the reaction that causes the brightening. The only issue could be puddles where unreacted ox remains, and even then I would only worry about pets and children. Even then, you're just misting the driveway, not laying down a deluge.
