bleach works great
Klenztone #! if all else fails: http://www.klenztone.com/
as a house keeperwe use bleech but macke sure to have a mask to cover your mouth and nose because the smell is strong
First of all if the spot is small use a wire brush and simple oven cleaner let it dry and rinse away oven cleaner works for all hard problems with concrete and stains and odor. Try it.
Other people asked questions on various topics, and are still waiting for answer. Would be great if you can take a sec and answer them