I am a huge fan of Simple Green, only because it is safe around food and stuff. In fact you can use it in slaughter houses its so safe, one of VERY few cleaners that are allowed around food. We used it a lot on the lobster boats too to kill the fish smell, and that is considered food areas as well. I don't mind the smell, which I consider pleasant I guess, which will cut the smell of the poo in the garage.
If that does not do the trick, I always grab my second favorite cleaner...WD-40. No kidding, that stuff is the miracle cleaner.
I have no intention of traveling from birth to the grave in a manicured and well preserved body; but rather I will skid in sideways, totally beat up, completely worn out, utterly exhausted and jump off my tractor and loudly yell, "Wow, this is what it took to feed a nation!"