You can’t scrub oil and grease stains away. The trick is to draw them up out of the concrete with trisodium phosphate (or a TSP substitute), water and an absorbent material. Patience is the key.

Luckily, by thoroughly cleaning the surface with trisodium phosphate, vinegar, or hydrogen peroxide, and then following up with an enzymatic cleaner, you'll be able to get rid of the stench of ...