With detachments of marauding Spartans harrying the city even when it wasn’t campaign season, disposing of privy waste outside of the city walls was no matter for cowards or bad businessmen. But where others saw a problem, Phales saw an opportunity. All he had to do was charge the same as everyone else, but eliminate the overhead of venturing outside the city walls. So while his income would be average, his costs would be much lower than average. He just needed to find a dumping ground inside the city walls.
One night as he contemplated the challenge, his mind somewhat befuddled by three kylixes of wine, he finally deciphered the words of the Pythia: Consider the waste of the body and tend to it. Dionysus yearns for you to flourish and sees you in the mire.
Waste of the body. Dionysus. Flourish. Mire. The oracle was telling him that Dionysus wants him to succeed and envisions him doing so by dumping body waste in the mire of the sacred Dionysian Marsh—where he and his men were at this very moment.